Flavanones are 2,3-dihydroflavones. Generally flavanones are prepared by condensation of 1,3-propanediones and aromatic aldehydes. In the present work, aromatic aldehyde was used to prepare 3-aroyl flavanones. Effect of chloro substitution in the aromatic ring of aldehyde was studied in terms of yield. Probable mechanism is also discussed. It is observed that due to introduction of chloro group in o/p position of aromatic aldehyde, the yield of product decreases due to deactivation of –CHO group for condensation with reactive methylene group.