diff --git a/databases/mongodb/README.md b/databases/mongodb/README.md
new file mode 100644
index 0000000..029ce14
--- /dev/null
+++ b/databases/mongodb/README.md
@@ -0,0 +1,81 @@
+AWS MongoDB Service DataDog monitors
+==========================================
+
+Link to integration documentation :
+
+[https://docs.datadoghq.com/integrations/mongo/](https://docs.datadoghq.com/integrations/mongo/)
+
+
+**Prepare your ReplicaSet** :
+
+Add a user to your ReplicaSet (on the primary instance)
+
+
+```
+use admin  
+db.auth("admin", "admin-password") ## This is optional is you don't have any admin password  
+db.createUser({"user":"datadog", "pwd": "{{PASSWORD}}", "roles" : [ {role: 'read', db: 'admin' }, {role: 'clusterMonitor', db: 'admin'}, {role: 'read', db: 'local' }]})
+```
+
+**Configure your Datadog agent**
+
+Add this file conf.d/mongo.yaml
+
+```
+
+init_config:
+
+instances:
+      -   server: mongodb://datadog:password@[MONGO_URI]
+          tags:
+              - mytag1
+              - mytag2
+      -   server: mongodb://datadog:password@[MONGO_URI]
+          tags:
+              - mytag1
+              - mytag2
+```
+
+**Monitor ReplicaSet Health**
+
+Name: [environment] Replica Set heath for {{ replset_name }}
+
+This monitor will check the health of your ReplicaSet
+
+Metrics are :
+
+1: The replicaSet is OK  
+0: The replicaSet is KO  
+
+This monitor will trigger an alert for each ReplicaSet.
+
+
+How to use this module
+----------------------
+
+```
+module "datadog-monitors-aws-mongodb" {
+  source = "git::ssh://git@bitbucket.org/morea/terraform.feature.datadog.git//databases/mongodb?ref={revision}"
+
+  message     = "${module.datadog-message-alerting.alerting-message}"
+  environment = "${var.environment}"
+
+}
+```
+
+Purpose
+-------
+
+Creates a DataDog monitors with the following checks : 
+* Mongodb ReplicaSet status
+
+Inputs
+------
+
+| Name | Description | Type | Default | Required |
+|------|-------------|:----:|:-----:|:-----:|
+| environment | Architecture Environment | string | - | yes |
+| evaluation_delay | Delay in seconds for the metric evaluation | string | `15` | no |
+| filter_tags_custom | Tags used for custom filtering when filter_tags_use_defaults is false | string | `*` | no |
+| filter_tags_use_defaults | Use default filter tags convention | string | `true` | no |
+| message | Message sent when an alert is triggered | string | - | yes |
diff --git a/databases/mongodb/inputs.tf b/databases/mongodb/inputs.tf
new file mode 100644
index 0000000..b698157
--- /dev/null
+++ b/databases/mongodb/inputs.tf
@@ -0,0 +1,25 @@
+# Global Terraform
+variable "environment" {
+  description = "Architecture Environment"
+  type        = "string"
+}
+
+# Global DataDog
+variable "evaluation_delay" {
+  description = "Delay in seconds for the metric evaluation"
+  default     = 15
+}
+
+variable "message" {
+  description = "Message sent when an alert is triggered"
+}
+
+variable "filter_tags_use_defaults" {
+  description = "Use default filter tags convention"
+  default     = "true"
+}
+
+variable "filter_tags_custom" {
+  description = "Tags used for custom filtering when filter_tags_use_defaults is false"
+  default     = "*"
+}
diff --git a/databases/mongodb/monitors-mongo.tf b/databases/mongodb/monitors-mongo.tf
new file mode 100644
index 0000000..03b55b8
--- /dev/null
+++ b/databases/mongodb/monitors-mongo.tf
@@ -0,0 +1,31 @@
+data "template_file" "filter" {
+  template = "$${filter}"
+
+  vars {
+    filter = "${var.filter_tags_use_defaults == "true" ? format("dd_monitoring:enabled,dd_monitoring_mongodb:enabled,env:%s", var.environment) : "${var.filter_tags_custom}"}"
+  }
+}
+
+resource "datadog_monitor" "mongodb_replicaset_state" {
+  name    = "[${var.environment}] Member down in the replica set"
+  message = "${var.message}"
+
+  query = <<EOF
+      avg(last_5m): (
+        avg:mongodb.replset.health{${data.template_file.filter.rendered}} by {region,replset_name}
+      ) < 1
+  EOF
+
+  type = "metric alert"
+
+  notify_no_data      = true
+  renotify_interval   = 0
+  evaluation_delay    = "${var.evaluation_delay}"
+  new_host_delay      = "${var.evaluation_delay}"
+  notify_audit        = false
+  timeout_h           = 0
+  include_tags        = true
+  require_full_window = true
+
+  tags = ["env:${var.environment}", "resource:mongodb"]
+}