A simple, precise and stability-indicating HPLC method was developed and validated for the simultaneous estimation of anti-retroviral drugs Lopinavir and Ritonavir. The separation was achieved on AgilentC8, 150mm* 4.6 ,5µ  column with isocratic flow. The mobile phase at a flow rate of 1.5ml consisted of 0.05M Potassium Dihydrogen Orthophosphate buffer and Acetonitrile: MeOH in the ratio of (80:20).The ratio of buffer: organic is (45:55).The UV detection was carried  out at 210nm. The method was successfully validated in accordance to ICH guidelines. This method was then used to study the stability aspects of both the drugs when subjected to acidic, alkaline, thermal and photo degradation condition.