The drugs Aceclofenac (ACF), Paracetamol (PAR), and Tramadol Hydrochloride (TH) are analgesics, and the combination is used in the symptomatic treatment of moderate to severe pain. The reported HPLC methods for this combination use complicated mobile phases; none is a stability-indicating method. The present study aims to develop and validate a simple stability-indicating RP-HPLC method for simultaneous estimating ACF, PAR, and TH in bulk and tablet dosage form. The chromatographic separation was performed using Neosphere C18 (250 x 4.6 mm, 5m) with a mobile phase comprising methanol: 0.5% Triethanolamine. 0.5% Triethanolamine was added to methanol to reduce tailing. The flow rate was set to 1.5ml/min and UV detection was carried out at 270 nm with a run time of 4 min. It was found to be linear in the range of 15-40 µg/ml, 39.9-106.4 µg/ml, and 129.9-346.4 µg/ml with a R 2 value of 0.999, 0.999, and 0.995 for TH, ACF and PAR respectively. Statistical analysis proved that the developed method is simple, accurate, precise, reproducible, specific, sensitive and costeffective. All three drugs were subjected to hydrolytic, acidic, basic, oxidative, thermal, and photodegradation. Degradation of PAR was found in oxidative and acidic conditions. ACF degradation was found in acidic conditions. Tramadol HCl showed degradation in every condition that was employed except hydrolytic condition.