diff --git a/README.md b/README.md
index 39f02949..48d27e97 100644
--- a/README.md
+++ b/README.md
@@ -72,6 +72,16 @@ post = Post.find '50b1386a0482939864000001' # Finds by bson ids
 ```
 [Examine slug.rb](lib/mongoid/slug.rb) for all available options.
 
+To set slugs for existing records run following rake task:
+
+```ruby
+rake mongoid_slug:set
+```
+You can pass model names as an option for which you want to set slugs:
+
+```ruby
+rake mongoid_slug:set[Model1,Model2]
+```
 Custom Slug Generation
 -------
 
diff --git a/lib/mongoid/slug.rb b/lib/mongoid/slug.rb
index 36eb94d1..3013e850 100644
--- a/lib/mongoid/slug.rb
+++ b/lib/mongoid/slug.rb
@@ -6,11 +6,17 @@
 require 'mongoid/slug/unique_slug'
 require 'mongoid/slug/slug_id_strategy'
 require 'mongoid-compatibility'
+require 'mongoid/slug/railtie' if defined?(Rails)
 
 module Mongoid
   # Slugs your Mongoid model.
   module Slug
     extend ActiveSupport::Concern
+    @classes = []
+
+    class << self
+      attr_accessor :classes
+    end
 
     included do
       cattr_accessor :reserved_words,
@@ -22,6 +28,7 @@ module Slug
 
       # field :_slugs, type: Array, default: [], localize: false
       # alias_attribute :slugs, :_slugs
+      Mongoid::Slug.classes << self
     end
 
     module ClassMethods
diff --git a/lib/mongoid/slug/railtie.rb b/lib/mongoid/slug/railtie.rb
new file mode 100644
index 00000000..c734d714
--- /dev/null
+++ b/lib/mongoid/slug/railtie.rb
@@ -0,0 +1,9 @@
+module Mongoid
+  module Slug
+    class Railtie < Rails::Railtie
+      rake_tasks do
+        Dir[File.join(File.dirname(__FILE__), '../../tasks/*.rake')].each { |f| load f }
+      end
+    end
+  end
+end
diff --git a/lib/tasks/mongoid_slug.rake b/lib/tasks/mongoid_slug.rake
new file mode 100644
index 00000000..81f31d02
--- /dev/null
+++ b/lib/tasks/mongoid_slug.rake
@@ -0,0 +1,16 @@
+namespace :mongoid_slug do
+  desc 'Goes though all documents and sets slug if not already set'
+  task set: :environment do |_, args|
+    ::Rails.application.eager_load! if defined?(Rails)
+    unless Mongoid::Slug.classes.blank?
+      models  = args.extras
+      klasses = Mongoid::Slug.classes
+      klasses = (klasses.map(&:to_s) & models.map(&:classify)).map(&:constantize) unless models.blank?
+      klasses.each do |klass|
+        # set slug for objects having blank slug
+        klass.each { |object| object.set_slug! unless object.slugs? }
+      end
+    end
+    p 'Completed mongoid_slug:set'
+  end
+end
diff --git a/spec/models/uninitalized_slug_first.rb b/spec/models/uninitalized_slug_first.rb
new file mode 100644
index 00000000..d0ee458b
--- /dev/null
+++ b/spec/models/uninitalized_slug_first.rb
@@ -0,0 +1,5 @@
+class UninitalizedSlugFirst
+  include Mongoid::Document
+  field :_id, type: Integer
+  field :name, type: String
+end
diff --git a/spec/models/uninitalized_slug_second.rb b/spec/models/uninitalized_slug_second.rb
new file mode 100644
index 00000000..10d56c94
--- /dev/null
+++ b/spec/models/uninitalized_slug_second.rb
@@ -0,0 +1,5 @@
+class UninitalizedSlugSecond
+  include Mongoid::Document
+  field :_id, type: Integer
+  field :name, type: String
+end
diff --git a/spec/models/uninitalized_slug_third.rb b/spec/models/uninitalized_slug_third.rb
new file mode 100644
index 00000000..d17ed11f
--- /dev/null
+++ b/spec/models/uninitalized_slug_third.rb
@@ -0,0 +1,5 @@
+class UninitalizedSlugThird
+  include Mongoid::Document
+  field :_id, type: Integer
+  field :name, type: String
+end
diff --git a/spec/tasks/mongoid_slug_rake_spec.rb b/spec/tasks/mongoid_slug_rake_spec.rb
new file mode 100644
index 00000000..835fdf77
--- /dev/null
+++ b/spec/tasks/mongoid_slug_rake_spec.rb
@@ -0,0 +1,52 @@
+require 'spec_helper'
+require 'rake'
+
+describe 'mongoid_slug:set' do
+  before :all do
+    load File.expand_path('../../../lib/tasks/mongoid_slug.rake', __FILE__)
+    Rake::Task.define_task(:environment)
+  end
+
+  context 'when models parameter is passed' do
+    let!(:uninitalized_slug1) { UninitalizedSlugFirst.create(id: 455, name: 'uninitalized_slug1') }
+    let!(:uninitalized_slug2) { UninitalizedSlugSecond.create(id: 456, name: 'uninitalized_slug2') }
+
+    it 'Goes though all documents of passed models and sets slug if not already set' do
+      class UninitalizedSlugFirst
+        include Mongoid::Slug
+        slug :name
+      end
+
+      class UninitalizedSlugSecond
+        include Mongoid::Slug
+        slug :name
+      end
+
+      expect(uninitalized_slug1.slugs).to be_nil
+      expect(uninitalized_slug2.slugs).to be_nil
+
+      Rake::Task['mongoid_slug:set'].reenable
+      Rake::Task['mongoid_slug:set'].invoke('UninitalizedSlugFirst')
+
+      expect(uninitalized_slug1.reload.slugs).to eq(['uninitalized-slug1'])
+      expect(uninitalized_slug2.reload.slugs).to eq []
+    end
+  end
+
+  context 'when models parameter is not passed' do
+    let!(:uninitalized_slug3) { UninitalizedSlugThird.create(id: 70, name: 'uninitalized_slug3') }
+
+    it 'Goes though all documents and sets slug if not already set' do
+      class UninitalizedSlugThird
+        include Mongoid::Slug
+        slug :name
+      end
+      expect(uninitalized_slug3.slugs).to be_nil
+
+      Rake::Task['mongoid_slug:set'].reenable
+      Rake::Task['mongoid_slug:set'].invoke
+
+      expect(uninitalized_slug3.reload.slugs).to eq(['uninitalized-slug3'])
+    end
+  end
+end