Chalcones are commonly found in fruit, vegetables, nuts, seeds, stems and flowers. For centuries, preparations containing these compounds as the principal bioactive constituents have been used to treat human diseases. Increasingly, this class of natural products is becoming the subject of antimicrobial research, and many groups have isolated and identified the structures of chalcones. However, several high-quality investigations have examined the relationship between chalcone structure and antibacterial activity and these are in close agreement. In addition, numerous research groups have sought to elucidate the antibacterial mechanisms of action of selected chalcones. Hence a series of some new chalcones have been synthesized by condensation of 3-acetyl-thiophene with various aromatic aldehydes in 40% alkali. The synthesized compounds were identified by spectral data and screened for antimicrobial activity.  Some of these compounds showed moderate to considerable anti-microbial activity. Key words: Chalcone, Synthesis, antimicrobial activity.