A highly sensitive and stable Graphene-Polyaniline-Bi2O3 (Grp-Pani-Bi2O3) composite film modified glassy carbon sensor was fabricated for electrochemical sensing of anti-inflammatory drug etodolac (ETD). The morphology was characterized by scanning electron microscopy and the electrochemical performance of the fabricated sensor was assessed by square wave and cyclic voltammetry. The influence of various parameters such as pH, effect of scan rate, and loading of Grp-Pani-Bi2O3 composite at GCE on analytical performance of the developed sensor was investigated. The excellent electrocatalytic activity of developed sensor results in good characteristics such as low potential detection of ETD, good stability, fast response, and anti-interferent ability. Oxidation peak current was linear over the target concentration with correlation coefficient of 0.9938. The limit of detection (LOD) and limit of quantification (LOQ) are 10.03 ng mL(-1) and 30.08 ng mL(-1) respectively. The proposed method was successfully applied to the determination of ETD in pharmaceutical formulation. The ease of fabrication, excellent electrochemical performance and high. electroactive surface area are the promising features of the fabricated sensor. (C) 2014 The Electrochemical Society.