A series of 1,3,5-triphenyl-2-pyrazoline derivatives were synthesized through microwave assisted condensation of 1,3-diphenyl-2-propene-1-one (chalcones) with phenylhydrazine using dry acetic acid as cyclizing agent and evaluated for antidepressant activity. The chemical structures of the compounds were confirmed by means of their IR, GC-MS and 1H NMR spectroscopic data. The antidepressant activity of these compounds were screened by porsolt behavioral despair test using imipramine as a reference drug. All synthesized 2-pyrazoline derivatives were found to possess significant antidepressant activity. It has been observed that 1,5-diphenyl-3- (4-methoxyphenyl)-2- pyrazoline showed maximum antidepressant activity, comparable with imipramine. A methoxy substituent on the phenyl ring at position 3 of the pyrazoline ring was found to enhance antidepressant activity. The replacement of the methoxy group by methyl and any other electron-withdrawing group decreases antidepressant activity.