Some heterocyclic systems namely stigmest-6-en-7, 5alpha thiourea and stigmest-6-en-7, 5alpha urea derivatives of steroids were synthesized by the reaction of stigmest-5-en-7 one with thiourea/urea in the presence of a few drops of conc. HCl at 80 degrees C in high yield. All the compounds have been characterized by means of elemental analyses, IR, 1H NMR, 13C NMR and mass spectroscopic data. The antibacterial activity was first tested in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria, and then the minimum inhibitory concentration (MIC) of compounds were determined. The results showed that steroidal thiourea derivatives inhibit growth as compared to steroidal urea derivatives of both type of the bacteria (Gram-positive and Gram-negative). Compounds 3 and 4 are better antibacterial agents as compared to standard drug chloramphenicol.