Pioglitazone use and risk of bladder cancer in diabetic patient is one of the major causes of morbidity and mortality. Increasing evidence from the clinical studies suggested increased risk of bladder cancer with higher dose and longer duration of pioglitazone use. In contrast, few studies reported non-significant association with pioglitazone use and risk of bladder cancer in T2DM patients. Therefore, we aimed to review and summarize the available clinical data describing the risk of bladder cancer associated with pioglitazone treatment.