A series of novel aliphatic sulfonamide derivatives (1-7) were synthesized and characterized by elemental analyses, FT-IR. H-1 NMR. C-13 NMR and LC-MS techniques. All the synthesized compounds were evaluated in vitro as antimicrobial agents against representative strairis of Gram-positive (Staphylococcus aureus ATCC 25953, Bacillus cereus ATCC 6633 and Listeria monocytogene ATCC Li6 (isolate), Gram-negative bacteria (Escherichia coli ATCC 11230) and antifungal agent against Candida albicans (clinical isolate) by both disc diffusion and minimal inhibition concentration (MIC) methods. All these bacteria and fungus studied were screened against some antibiotics to compare with our chemicals' zone diameters. Our aliphatic sulfonamides have highest powerful antibacterial activity for Gram-negative bacteria than Gram-positive bacteria and antibacterial activity decreases as the length of the carbon chain increases. Published by Elsevier Ltd.