Abstract. Many stages of interconnected switching elements (SEs) forms a Multistage interconnection networks (MIN) which has high-speed, low cost and high reliability and used for parallel processing, broadband switching technology etc. Executing a task with good performance in faulty condition is very significant in a MIN. That’s why fault tolerance in MINs is a very challenging issue in present research scenario. A new fault tolerant irregular MIN named as Modified Irregular Omega Networks (MION) is proposed in this research paper. The MION is a double switch fault tolerant MIN and it performs better fault tolerance than existing Irregular Advanced Omega Network (IAON) under non-faulty and faulty network environment.