A series of thiophenol adducts (3a–m) were prepared by addition of thiophenol to chalcones (1a–m) in the presence of a catalytic amount of KOt-Bu in solvent free conditions. In addition, the antibacterial and antifungal in vitro properties were tested against some human pathogenic microorganisms by employing the disk diffusion technique. A majority of compounds were remarkably active against several of the microorganisms. Compound 3i was determined to be the most active compound.