Many computer problems today need the computer power that is only available using large scale parallel processing. For a significant number of these problems, the density of the global communications between the individual processors dominates the performance of the whole parallel implementation on a distributed memory multiprocessor system. In these cases, the design of the interconnection network for the processors is known to play a significant part in the efficient implementation of real problems. Networks of processors connected as an irregular configuration have the advantage that they satisfy the best known criteria for producing configurations that perform well on real applications. This paper presents a new genetic algorithm for the generation of optimal irregular configurations, which is a challenging problem since there is no obvious representation which allows all the main genetic operations to be implemented effectively.