Aspect Oriented Programming proposes an approach to increase code functionality with aspects that are not part of the main code functionality. The current work shows how can be done AOP in .NET thanks to one of the most interesting .NET innovations: its capacity to put custom metadata inside a software component by means of .NET attributes. This paper defines different kinds of such attributes to represent aspects and shows how the functionality embedded in the attributes can be integrated with the functionality of the code decorated by them. Such aspect-attributes are inserted into an existing .NET component without forcing reprogramming the client code of the component. Then the code of the aspect functionality is woven into the code of the component.