Routing and Wavelength Assignment (RWA) is a well known problem in Wavelength Division Multiplexing (WDM) networks. RWA problem is reported in the literature as a single objective ILP problem. In this article, we formulated the RWA problem as a multi objective ILP problem. An attempt is made to obtain a feasible solution using genetic algorithm (GA). The parameters considered for optimization are congestion among the individual lightpath requests, connection set up time, the number of intermediate hops traversed and the number of fibers used to honor the established connection requests. We considered ARPANET and NSFNET for our simulation.