diff --git a/handler/crash_report_upload_thread.cc b/handler/crash_report_upload_thread.cc
index c13bbf4b..d77cdbad 100644
--- a/handler/crash_report_upload_thread.cc
+++ b/handler/crash_report_upload_thread.cc
@@ -35,6 +35,10 @@
 #include "util/net/http_transport.h"
 #include "util/stdlib/map_insert.h"
 
+#if defined(OS_MACOSX)
+#include "handler/mac/file_limit_annotation.h"
+#endif  // OS_MACOSX
+
 namespace crashpad {
 
 namespace {
@@ -228,6 +232,10 @@ void CrashReportUploadThread::ProcessPendingReports() {
 
 void CrashReportUploadThread::ProcessPendingReport(
     const CrashReportDatabase::Report& report) {
+#if defined(OS_MACOSX)
+  RecordFileLimitAnnotation();
+#endif  // OS_MACOSX
+
   Settings* const settings = database_->GetSettings();
 
   bool uploads_enabled;
diff --git a/handler/handler.gyp b/handler/handler.gyp
index d6e4c271..50479828 100644
--- a/handler/handler.gyp
+++ b/handler/handler.gyp
@@ -43,6 +43,8 @@
         'mac/crash_report_exception_handler.h',
         'mac/exception_handler_server.cc',
         'mac/exception_handler_server.h',
+        'mac/file_limit_annotation.cc',
+        'mac/file_limit_annotation.h',
         'prune_crash_reports_thread.cc',
         'prune_crash_reports_thread.h',
         'user_stream_data_source.cc',
diff --git a/handler/handler_main.cc b/handler/handler_main.cc
index b4a08c51..e6d05e22 100644
--- a/handler/handler_main.cc
+++ b/handler/handler_main.cc
@@ -61,6 +61,7 @@
 #include "base/mac/scoped_mach_port.h"
 #include "handler/mac/crash_report_exception_handler.h"
 #include "handler/mac/exception_handler_server.h"
+#include "handler/mac/file_limit_annotation.h"
 #include "util/mach/child_port_handshake.h"
 #include "util/mach/mach_extensions.h"
 #include "util/posix/close_stdio.h"
@@ -697,6 +698,8 @@ int HandlerMain(int argc,
       reset_sigterm.reset(&old_sigterm_action);
     }
   }
+
+  RecordFileLimitAnnotation();
 #elif defined(OS_WIN)
   // Shut down as late as possible relative to programs we're watching.
   if (!SetProcessShutdownParameters(0x100, SHUTDOWN_NORETRY))
diff --git a/handler/mac/crash_report_exception_handler.cc b/handler/mac/crash_report_exception_handler.cc
index 7d3d6297..6f9cdbe6 100644
--- a/handler/mac/crash_report_exception_handler.cc
+++ b/handler/mac/crash_report_exception_handler.cc
@@ -21,6 +21,7 @@
 #include "base/mac/scoped_mach_port.h"
 #include "base/strings/stringprintf.h"
 #include "client/settings.h"
+#include "handler/mac/file_limit_annotation.h"
 #include "minidump/minidump_file_writer.h"
 #include "minidump/minidump_user_extension_stream_data_source.h"
 #include "snapshot/crashpad_info_client_options.h"
@@ -67,6 +68,7 @@ kern_return_t CrashReportExceptionHandler::CatchMachException(
     mach_msg_type_number_t* new_state_count,
     const mach_msg_trailer_t* trailer,
     bool* destroy_complex_request) {
+  RecordFileLimitAnnotation();
   Metrics::ExceptionEncountered();
   Metrics::ExceptionCode(ExceptionCodeForMetrics(exception, code[0]));
   *destroy_complex_request = true;
diff --git a/handler/mac/file_limit_annotation.cc b/handler/mac/file_limit_annotation.cc
new file mode 100644
index 00000000..359ed8e0
--- /dev/null
+++ b/handler/mac/file_limit_annotation.cc
@@ -0,0 +1,93 @@
+// Copyright 2017 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "handler/mac/file_limit_annotation.h"
+
+#include <errno.h>
+#include <sys/resource.h>
+#include <sys/sysctl.h>
+#include <sys/types.h>
+
+#include <string>
+
+#include "base/format_macros.h"
+#include "base/macros.h"
+#include "base/strings/stringprintf.h"
+#include "client/crashpad_info.h"
+#include "client/simple_string_dictionary.h"
+
+namespace {
+
+// rv is the return value from sysctl() or sysctlbyname(), and value and size
+// are the pointers passed as oldp and oldlenp. If sysctl() failed, the returned
+// string will be "E" followed by the error number. If there was a size
+// mismatch, the returned string will be "Z" followed by the size indicated by
+// sysctl(). Normally, a string representation of *value will be returned.
+std::string FormatFromSysctl(int rv, const int* value, const size_t* size) {
+  if (rv != 0) {
+    return base::StringPrintf("E%d", errno);
+  }
+  if (*size != sizeof(*value)) {
+    return base::StringPrintf("Z%zu", *size);
+  }
+  return base::StringPrintf("%d", *value);
+}
+
+// Returns a string for |limit|, or "inf" if |limit| is RLIM_INFINITY.
+std::string StringForRLim(rlim_t limit) {
+  if (limit == RLIM_INFINITY) {
+    return std::string("inf");
+  }
+
+  return base::StringPrintf("%" PRIu64, limit);
+}
+
+}  // namespace
+
+namespace crashpad {
+
+void RecordFileLimitAnnotation() {
+  CrashpadInfo* crashpad_info = CrashpadInfo::GetCrashpadInfo();
+  SimpleStringDictionary* simple_annotations =
+      crashpad_info->simple_annotations();
+  if (!simple_annotations) {
+    simple_annotations = new SimpleStringDictionary();
+    crashpad_info->set_simple_annotations(simple_annotations);
+  }
+
+  int value;
+  size_t size = sizeof(value);
+  std::string num_files = FormatFromSysctl(
+      sysctlbyname("kern.num_files", &value, &size, nullptr, 0), &value, &size);
+
+  int mib[] = {CTL_KERN, KERN_MAXFILES};
+  size = sizeof(value);
+  std::string max_files = FormatFromSysctl(
+      sysctl(mib, arraysize(mib), &value, &size, nullptr, 0), &value, &size);
+
+  rlimit limit;
+  std::string nofile;
+  if (getrlimit(RLIMIT_NOFILE, &limit) != 0) {
+    nofile = base::StringPrintf("E%d,E%d", errno, errno);
+  } else {
+    nofile =
+        StringForRLim(limit.rlim_cur) + "," + StringForRLim(limit.rlim_max);
+  }
+
+  std::string annotation = base::StringPrintf(
+      "%s,%s,%s", num_files.c_str(), max_files.c_str(), nofile.c_str());
+  simple_annotations->SetKeyValue("file-limits", annotation.c_str());
+}
+
+}  // namespace crashpad
diff --git a/handler/mac/file_limit_annotation.h b/handler/mac/file_limit_annotation.h
new file mode 100644
index 00000000..1131986e
--- /dev/null
+++ b/handler/mac/file_limit_annotation.h
@@ -0,0 +1,38 @@
+// Copyright 2017 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CRASHPAD_HANDLER_MAC_FILE_LIMIT_ANNOTATION_H_
+#define CRASHPAD_HANDLER_MAC_FILE_LIMIT_ANNOTATION_H_
+
+namespace crashpad {
+
+//! \brief Records a `"file-limits"` simple annotation for the process.
+//!
+//! This annotation will be used to confirm the theory that certain crashes are
+//! caused by systems at or near their file descriptor table size limits.
+//!
+//! The format of the annotation is four comma-separated values: the system-wide
+//! `kern.num_files` and `kern.maxfiles` values from `sysctl()`, and the
+//! process-specific current and maximum file descriptor limits from
+//! `getrlimit(RLIMIT_NOFILE, …)`.
+//!
+//! See https://crashpad.chromium.org/bug/180.
+//!
+//! TODO(mark): Remove this annotation after sufficient data has been collected
+//! for analysis.
+void RecordFileLimitAnnotation();
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_HANDLER_MAC_FILE_LIMIT_ANNOTATION_H_