Recebido em 8/7/11; aceito em 29/11/11; publicado na web em 23/1/12 A rapid and sensitive method using high performance liquid chromatography has been developed and validated for the simultaneous determination of non-steroidal anti-inflammatory drugs (NSAIDs) in pharmaceutical formulations and human serum. Six NSAIDs including: naproxen sodium, diclofenac sodium, meloxicam, flurbiprofen, tiaprofenic and mefenamic acid were analyzed simultaneously in presence of ibuprofen as internal standard on Mediterranea C 18 (5 µm, 250 x 0.46 mm) column. Mobile phase comprised of methanol: acetonitrile: H 2 O (60:20:20, v/v; pH 3.35) and pumped at a flow rate of 1 mL min -1 using 265 nm UV detection. The method was linear over a concentration range of 0.25-50 μg mL -1 (r 2 = 0.9999).