An Inset fed E-Shape microstrip Patch Antenna has been developed and simulated for operation of Industrial, Scientific and Medical (ISM) band (2.40-2.52 GHz). The patch antenna is simulated using IE3D® EM simulator (version 14.0) and optimized with an evolutionary stochastic optimizer i.e. Particle Swarm Optimization (PSO) technique. Optimized results show that the antenna is working in ISM frequency band. These bands include the designated frequency bands of wireless standards IEEE 802.11, 802.11b, 802.15.2 and Bluetooth. The antenna exhibits good radiation characteristics and moderate gain in the entire operating band. © 2011 ISRAMT.