Bacteriostatic efficacy of 16 crude extracts derived from different parts of Argemone mexicana Linn. (Papaveraceae) has been analyzed on entropathogenic bacteria such as Klebsiella oxytoca, Vibrio damsella, Enterobacter aerogenes and Escherichia coli. The bacteriostatic efficacy was elucidated using single disc diffusion method. The minimum inhibitory concentration (MIC) of the extracts showing higher efficacy against the test organisms was determined. The MICs of acetone extract of seed and aqueous extract of leaf on different bacteria tested were found to be between 0.005-0.02 mg/disc.