Medicinal plants have been used virtually in all cultures as a source of medicine. The fresh leaves of in vivo grown and in vitro grown plants of Evolvulus alsinoides, Evolvulus nummularius, and Merremia tridentata were collected and examined for antimicrobial activity. Zone and turbidity methods are employed for antimicrobial assay. Methanolic extracts of the leaf parts of in vivo and in vitro grown cultures have exhibited antimicrobial activity. The extracts are found to be more effective against gram-positive bacteria and yeast (MIC of 0.05 to 0.25mg/ml) than gram-negative bacteria (MIC of 0.25 to 50 mg/ml). The extracts are found to be more effective against bacteria rather than filamentous fungi. The zone formation and MIC results from in vitro grown leaf extracts were less compared to the in vivo grown leaf extracts.