A simple, accurate and specific proton magnetic resonance (PMR) procedure was developed for the assay of tiaprofenic acid and its tablets. The method involves comparing the integral of the nice doublet signal of tiaprofenic acid (positioned at 1.60 δ) to that of the sharp singlet signal (positioned at 2. 1 δ) of acetanilide which is used as internal standard. The method reported in this study gives accurate and reproducible results; 100. 16 ± 0. 23% for authentic tiaprofenic acid and 100.00 ± 1. 05% for tiaprofenic acid tablets (SurgamR). In addition, the PMR spectrum obtained helps in confirming the identify and purity of the drug.