A series of N-alkyl substituted urea derivatives were synthesized and evaluated for their in vitro antibacterial and antifungal activities. The N-alkyl substituted urea derivatives bearing morpholine moiety (3a–3k) showed better activities than those bearing diethylamine moiety (2a–2f). Compounds having fluoro substituent at ortho (3c) and para (3b) positions of the phenyl ring exhibited potent antimicrobial