Eight microelectrodes based on the complexes of zinc with porphyrins or phthalocyanines immobilized in carbon or diamond paste matrices were proposed for the assay of oseltamivir phosphate in its pharmaceutical formulation using differential pulse voltammetry (DPV). The limits of detection were between 3.64 x 10(-14) and 8.17 x 10(-9) mol/L. Oseltamivir phosphate was recovered reliable from pharmaceutical and biological samples in percentages higher than 91.00%. The surface of the microelectrodes can easily be renewed by simple polishing on aluminum foil, obtaining a fresh surface ready for use. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.001209jes] All rights reserved.