The stability of the broad-spectrum antibiotic ceftiofur was studied in order to investigate the kinetics of photodegradation of this drug, using a stability-indicating liquid chromatography (LC) method. The degradation was carried out in aqueous solutions, prepared from reference substance and two pharmaceutical products (Excenel® and Topcef®) containing sodium ceftiofur powder for injection, in quartz cells under UVC ( 254 nm) and UVA light (352 nm). The kinetics parameters of reaction order and the rate constants of the degradation were determined for both products. The degradation process of sodium ceftiofur in solution can be described by first-order kinetics under the experimental conditions used in this study. The obtained results show that the LC method is satisfactory in the determination of the kinetics of degradation of sodium ceftiofur in the presence of its photolytic degradation products. The present study reveals the photolability of the drug. Thus, appropriate light protection is recommended during the storage and handling of products containing sodium ceftiofur.