In this study 18 new hydrazones have been synthesized by reacting ortho- or para-substituted acetophenones with (3-substituted-1,2,4-triazol-5-yl-thio)acetohydrazide in ethanol. The prepared compounds were tested for antimicrobial activity. The prepared compounds exhibited only poor activity against Gram (+) and Gram (-) bacteria with the minimal inhibitory concentration (MIC) greater than or equal to 400 mu g/ml. Moderate activity was observed against Candida species with MIC in the range 100-400 mu g/ml. (C) 1998 Elsevier Science S.A. All rights reserved.