Schiff bases and thiazolidinone derivatives of 5-amino-1H-imidazole -4-carboxamide have been prepared and tested for pharmacological activities. Schiff base derivatives have been obtained by reacting 5-amino-1H-imidazole -4- carboxamide with suitable aromatic aldehyde which were further converted to thiazolidinone derivatives by reaction of Schiff bases with mercaptoacetic acid. The structure of synthesized compounds have been established on the basis of their spectral (IR, 1H NMR and mass) data. The purity of the synthesized compounds was confirmed by TLC. Good level of pharmacological activity has been displayed by both categories of compounds against tested pathogenic microorganism. Thiazolidinone derivatives (2a-f) showed higher activity than schiff base derivatives (1a-f).