Department of Chemistry, Bhavnagar University, Bhavnagar-364 002, Gujarat, India E-mail : drgodhani@yahoo.com Manuscript received 8 February 2007, revised 1 January 2008, accepted 21 February 2008 A series of 4-oxo-2-phenyl-thiazolidin-3-yl derivatives 5a-1 have been obtained by cyclisation of various Schiff's base 4 with thioglycolic acid. The Schiff's base 4 are obtained by the reaction of appropriate carbonyl compound with (4-oxo-3-p-tolyl-3,4-dihydro-quinazolin-2-yl-sulfanyl)-acetic acid hydrazide 3. The product is characterized by spectral and analytical data. Most of the tested compounds show promising antibacterial and antifungal activity.