The voltammetric behavior of cefdinir has been studied in different surfactant media viz. anionic, neutral, and cationic surfactants over the pH range 2.5-12 in phosphate buffer (0.2 M). Addition of cationic surfactant (citrimide) to the cefdinir containing electrolyte enhanced the reduction current signal while anionic surfactant (sodium lauryl) and neutral surfactant (Tween-20) showed an opposite effect. The reduction process was irreversible over the entire pH range studied (2.5-12). The mechanism of reduction has been postulated on the basis of controlled potential electrolysis, coulometry and spectral analysis. An analytical method with adequate precision and accuracy was developed for the determination of cefdinir in linear concentration range 2 x 10(-4)-1 x 10(-5) mol L-1 with detection limit 0.3 x 10(-6) mol L-1. The analysis of cefdinir in its pharmaceutical formulation resulted in mean recoveries of 99 and 98% for both the reduction peaks. (c) 2007 Elsevier Inc. All rights reserved.