The mesh plug technique is one of the most popular procedures for inguinal hernia repair in Japan. This procedure is quick, easy, and low cost with a low recurrence rate. However, some complications associated with the mesh plug have been reported recently. We hereby present a case of an 80-year-old female admitted to our hospital with swelling and pain in the right lower abdomen 5 years after hernia repair with the PerFix plug. Discharge of urine through the route of exploratory needle puncture demonstrated the fistula of skin and the bladder. Computed tomography (CT), magnetic resonance imaging (MRI), abdominal US, and cystoscope examination revealed that the mesh plug had penetrated into the bladder. As far as we know, this is the first report that a mesh plug has migrated into the bladder.