A fluorometric procedure for procainamide hydrochloride was developed, and it offers improvements in ease, speed, and sensitivity over the official method. The new procedure is based on the reaction with fluorescamine in aqueous medium at pH 7.5 to form a fluorophore, with activation and emission wavelengths of 400 and 485 nm, respectively. The fluorescence is linear (r = 0.999) over the 0. 04-1 mug/ml concentration range and is stable for at least 2 hr. Recovery data appeared to be accurate, quantitative, and reproducible. The overall recovery was 99.8% with a standard deviation of +/-1.14 (n = 5). The method was successfully applied to commercially available dosage forms.