A set of new aziridinyl phosphonates (4a-g) were synthesized by using the Gabriel-Cromwell reaction and its modified version developed in this study and their structures confirmed by HRMS, IR. and NMR spectra. All the compounds were screened for their antibacterial activity. They all showed comparable moderate to good growth inhibitory activity in reference to ampicillin and streptomycin. (C) 2011 Elsevier Masson SAS. All rights reserved.