diff --git a/docs/20_Checks/_index.md b/docs/20_Checks/_index.md
index 839ca53eaba1e5f82ea2c6f69cf8eb4328c41c8d..04adc02e6e43d8929d8c594dc1a4529b2139206b 100644
--- a/docs/20_Checks/_index.md
+++ b/docs/20_Checks/_index.md
@@ -40,6 +40,7 @@ There is one include script used by all checks:
 * check_proc_ressources
 * check_proc_zombie
 * [check_psqlserver](check_psqlserver.md)
+* [check_rearbackup](check_rearbackup.md)
 * [check_reboot_required](check_reboot_required.md)
 * check_requirements
 * check_sensuplugins
diff --git a/docs/20_Checks/check_rearbackup.md b/docs/20_Checks/check_rearbackup.md
new file mode 100644
index 0000000000000000000000000000000000000000..c718824289b193b212513100b609402f678d389b
--- /dev/null
+++ b/docs/20_Checks/check_rearbackup.md
@@ -0,0 +1,89 @@
+# Check Rear backup
+
+## Introduction
+
+This check can verify the age of all iso files in the backup target directory.
+
+## Requirements
+
+There can be a permission issue to reach the backup target directory.
+On our servers the backup target is using a user *imlbackup*. To give access to its resources we added the group "imlrear" for icinga.
+
+```txt
+$ id icingaclient
+uid=1041(icingaclient) gid=1041(icingaclient) groups=1041(icingaclient),1056(imlrear)
+                                                                             ^
+                                                                             |
+                                additional group for icinga client user -----+
+```
+
+## Syntax
+
+```txt
+______________________________________________________________________
+
+CHECK_REARBACKUP
+v1.0
+
+(c) Institute for Medical Education - University of Bern
+Licence: GNU GPL 3
+
+https://os-docs.iml.unibe.ch/icinga-checks/Checks/check_rearbackup.html
+______________________________________________________________________
+
+Check if iso files of rear backup are not out of date.
+You can customize the values for
+* backup directory
+* limits for warning and critical
+
+This plugin sends performancedata.
+
+SYNTAX:
+
+  check_rearbackup [-h] [--dir PATH] [--critical VALUE] [--warning VALUE]
+
+OPTIONS:
+
+  -h, --help 
+      this help
+
+PARAMETERS:
+
+  -d, --dir PATH
+      set installation dir of iml deployment to find its check skript
+      default dir: /rearshare/rear-backup
+
+  -c, --critical VALUE
+      critical level in days (default: 14)
+
+  -w. --warning VALUE
+      warning level in days (default: 7)
+
+EXAMPLE:
+
+  check_rearbackup
+      Check backup data with initial values
+
+  check_rearbackup -d /data/mybackups
+      Check iso files a given directory
+    
+  check_rearbackup -d /data/mybackups -w 14 -c 28
+      Check iso files a given directory and customized limits
+
+```
+
+## Examples
+
+### Rear backup status
+
+```txt
+# ./check_rearbackup
+CRITICAL: Rear backup /rearshare/rear-backup - 20 total - 0 critical (7 d) .. 2 warnings (14 d) .. 18 OK
+
+All iso files in alphabetic order:
+OK          4 d ####        -rw-rw-r--. 1 imlrear imlrear 3907082240 Dec 17 10:28 /rearshare/rear-backup/admin/admin.example.com_backup.iso
+OK          5 d #####       -rw-rw-r--. 1 imlrear imlrear 573384704 Dec 16 18:07 /rearshare/rear-backup/awx/awx.example.com_backup.iso
+(...)
+
+|ok=18;;;0;20 warning=2;;;0;20 critical=0;;;0;20
+```