Bupropion is a medication commonly used to treat depression and help people quit smoking. However, it has the potential to be misused or diverted, so it is important to have accurate and sensitive methods to detect it in bodily fluids. We present a fast and dependable quantitative LC-MS/MS method for measuring bupropion levels in urine. This method involves enzymatic hydrolysis and separation using a reversed-phase C18 column, where the effectiveness of the hydrolysis is monitored using morphine-3-b-D-glucuronide. The analysis is conducted using an AB Sciex 3500 mass spectrometer with dual-channel LC system.