diff --git a/lib/oga/xml/element.rb b/lib/oga/xml/element.rb
index f4aebec..cde3ff9 100644
--- a/lib/oga/xml/element.rb
+++ b/lib/oga/xml/element.rb
@@ -96,6 +96,48 @@ module Oga
         return found ? found.value : nil
       end
 
+      ##
+      # Adds a new attribute to the element.
+      #
+      # @param [Oga::XML::Attribute] attribute
+      #
+      def add_attribute(attribute)
+        attribute.element = self
+
+        attributes << attribute
+      end
+
+      ##
+      # Sets the value of an attribute to the given value. If the attribute does
+      # not exist it is created automatically.
+      #
+      # @param [String] name The name of the attribute, optionally including the
+      #  namespace.
+      #
+      # @param [String] value The new value of the attribute.
+      #
+      def set(name, value)
+        found = attribute(name)
+
+        if found
+          found.value = value
+        else
+          if name.include?(':')
+            ns, name = name.split(':')
+          else
+            ns = nil
+          end
+
+          attr = Attribute.new(
+            :name           => name,
+            :namespace_name => ns,
+            :value          => value
+          )
+
+          add_attribute(attr)
+        end
+      end
+
       ##
       # Returns the namespace of the element.
       #
diff --git a/spec/oga/xml/element_spec.rb b/spec/oga/xml/element_spec.rb
index ae46c48..047c606 100644
--- a/spec/oga/xml/element_spec.rb
+++ b/spec/oga/xml/element_spec.rb
@@ -101,6 +101,63 @@ describe Oga::XML::Element do
     end
   end
 
+  context '#add_attribute' do
+    before do
+      @element   = described_class.new
+      @attribute = Oga::XML::Attribute.new(:name => 'foo', :value => 'bar')
+    end
+
+    example 'add an Attribute to the element' do
+      @element.add_attribute(@attribute)
+
+      @element.attribute('foo').should == @attribute
+    end
+
+    example 'set the element of the attribute when adding it' do
+      @element.add_attribute(@attribute)
+
+      @attribute.element.should == @element
+    end
+  end
+
+  context '#set' do
+    before do
+      @element = described_class.new
+
+      @element.register_namespace('x', 'test')
+    end
+
+    example 'add a new attribute' do
+      @element.set('class', 'foo')
+
+      @element.get('class').should == 'foo'
+    end
+
+    example 'add a new attribute with a namespace' do
+      @element.set('x:bar', 'foo')
+
+      @element.get('x:bar').should == 'foo'
+    end
+
+    example 'set the namespace of an attribute' do
+      @element.set('x:bar', 'foo')
+
+      attr = @element.attribute('x:bar')
+
+      attr.namespace.is_a?(Oga::XML::Namespace).should == true
+    end
+
+    example 'overwrite the value of an existing attribute' do
+      attr = Oga::XML::Attribute.new(:name => 'foo', :value => 'bar')
+
+      @element.add_attribute(attr)
+
+      @element.set('foo', 'baz')
+
+      @element.get('foo').should == 'baz'
+    end
+  end
+
   context '#namespace' do
     before do
       @namespace = Oga::XML::Namespace.new(:name => 'x')