Bisphenol-A (BPA) biodegradation was studied in a membrane bioreactor under aerobic conditions. The effects of the initial BPA concentration and initial chemical oxygen demand (COD) concentration on BPA biodegradation were investigated. The degradation process followed a first-order kinetic (more than 98% of BPA was removed) with a kinetic rate constant of 1.134 h−1 using an initial BPA concentration of 1.0 mg L−1. The kinetic rate constant decreased to 0.611 h−1 when the initial BPA concentration increased to 5.0 mg L−1. The initial COD concentration (400 and 2,000 mg L−1) did not affect the biodegradation kinetic of BPA.