Dapsone is the drug of choice for leprosy treatment. Despite the existence of previous analytical methods, this study aimed to develop a new analytical alternative for dapsone quantification by UV spectrophotometry. Since the pharmacopeial method uses methanol, a toxic solvent, the method was developed using first dilution in ethanol (500 μg/mL) and second dilution in water (5 μg/mL), with quantification in 295 nm. For validation, the specificity was confirmed by quantification of degraded samples using the developed method in comparison with a second analytical technique (HPLC-DAD). The proposed method proved to be specific, linear, precise, accurate and robust, with analytical low cost and toxicity, besides presenting operational ease.