diff --git a/ruby_redis_monitor_nagios.rb b/ruby_redis_monitor_nagios.rb
new file mode 100644
index 0000000..10622c5
--- /dev/null
+++ b/ruby_redis_monitor_nagios.rb
@@ -0,0 +1,46 @@
+#!/usr/bin/env ruby
+require 'optparse'
+options  = {}
+required = [:warning, :critical, :host]
+
+parser   = OptionParser.new do |opts|
+    opts.banner = "Usage: check_redis_replication [options]"
+      opts.on("-h", "--host redishost", "The hostname of the redis slave") do |h|
+        options[:host] = h
+      end
+      opts.on("-w", "--warning percentage", "Warning threshold") do |w|
+        options[:warning] = w
+      end
+      opts.on("-c", "--critical critical", "Critical threshold") do |c|
+        options[:critical] = c
+      end
+end
+parser.parse!
+abort parser.to_s if !required.all? { |k| options.has_key?(k) }
+
+master_last_io_seconds_ago = `redis-cli info | grep master_last_io_seconds_ago`.split(':').last.to_i rescue -1
+
+status = <img src="http://s1.wp.com/wp-includes/images/smilies/icon_surprised.gif?m=1129645325g" alt=":o" class="wp-smiley"> k
+if master_last_io_seconds_ago < 0 || master_last_io_seconds_ago >= options[:critical].to_i
+    status = :critical
+elsif master_last_io_seconds_ago >= options[:warning].to_i
+    status = :warning
+end
+
+status_detail = master_last_io_seconds_ago == -1 ? 'ERROR' : "#{ master_last_io_seconds_ago.to_s }s"
+puts "#{status.to_s.upcase} - replication lag: #{status_detail}"
+
+if status == :critical
+    exit(2)
+elsif status == :warning
+    exit(1)
+end
+
+
+define service {
+      name                            redis_replication
+      register                        1
+      check_command                   check_nrpe!check_redis_replication!$HOSTNAME$ 100 250
+      service_description             Redis Replication
+      hostgroup_name                  redis_slave
+}