Abstract. Aspect-Oriented Software Development (AOSD) provides better design solutions to problems where Object Oriented Development produces tangled and scattered designs. Nevertheless, there are still several problems for which AOSD is not helpful. An example is the implementation of some design patterns. While it has been shown that some of them can be implemented in a domain-independent way by the use of AOSD [1], there is still a group of them for which current AOSD techniques are of little use. This paper proposes to extend Aspect Oriented Languages with parametric aspects. This extension can integrate seamlessly into Aspect Oriented Languages like AspectJ, and allows to provide a better design solution for problems for which current AOSD techniques are of little help, improving software reuse and reducing its complexity, thus facilitating the software evolution process. Two representative examples are used in order to expose the proposed extension: ementation of the abstract fac...