Synthesis of new cyclopentenone derivatives by reacting 1-acetyl-1-cyclohexene with various aromatic and heteroaromatic aldehydes is reported. All the new cyclopentenone derivatives were characterized by 1 H, 13 C NMR, IR and mass spectral data, and were further screened for their antimicrobial activity. Most of the compounds showed comparable activities with standard drug ciprofloxacin and in particular, compounds 3d, 3f, 3g and 3j showed excellent activity against all the four bacterial strains.