Some new trisubstituted purinyl thioureido were synthesized and evaluated for their in vitro antimicrobial activity against Gram positive and Gram negative strains and antifungal strain using a micro dilution procedure. Synthesized compounds 6a–j prove to be effective with minimum inhibitory concentration (MIC) (mg ml-1 ), among them 6a, 6d, and 6e showed excellent activity against a panel of microorganisms. The newly synthesized compounds were characterized using IR, 1 H-NMR, and elemental analysis.