We report a simple and sensitive voltammetric sensor for the determination of chlorpromazine (CPZ) based on Ni−Al layered double hydroxide (NiAlLDH) modified glassy carbon electrode (GCE). NiAlLDH was simply electrodeposited on GCE surface in a very short time. The response linear range was 1×10−3–1×10−9 mol L−1, with a detection limit of 1×10−9 mol L−1. The NiAlLDH film showed well defined and well separate peaks for dopamine, ascorbic acid, uric acid and CPZ in the same solution. The proposed electrode was used to measure the active pharmaceutical ingredient of CPZ tablet as a real sample.