A simple, robust and selective and sensitive spectrophotometric method has been developed for the determination of Ritonavir in pharmaceutical formulations. The method was based on the scanning of methanolic solution of the drug and methanolic solution of formulation. The method showed high sensitivity with linearity range from 10 to 20 μg/mL. The lower limit of detection (LOD) was found to be 1.1 μg/mL and the limit of quantization (LOQ) was determined as the lowest concentration was found to be 3.3 μg/mL. The variables that affected the reaction were carefully studied and optimized. The proposed method was applied successfully for the determination of Ritonavir in pharmaceutical formulations. The percentage recovery was found to be 99.426 ± 0.59 (n = 9) for pharmaceutical formulation.