Aim & Objective: In vitro analysis of the anti-diabetic effect of aqueous extracts from the medicinal plants Hemidesmus indicus, Ficus benghalensis, Pterocarpus marsupium roxb.Materials & Methods: An aqueous extract of each of the plants were prepared by soxhletion at 60o C. 1mL of the extract was then placed in a bio-membrane along with a glucose solution (0.22 mM in 0.15 M NaCl) and the bio-membrane was immersed in a beaker containing 40mL of 0.15 M NaCl + 10mL of distilled water. The control contained 1mL of 0.15 M NaCl containing 22 mM glucose and 1mL of distilled water. Half-hourly observations of the concentration of glucose in mg/dL in the beaker were done. Results:A significant hindrance to the flow of glucose across the bio-membrane was seen. Pterocarpus marsupiumroxb and Ficus benghalensis showed a relative movement of 16.05% (p<0.01) and 78% (p<0.01) when compared to the aqueous control after 180 minutes. Hemidesmus indicus showed a relative movement of 84.5% (p<0.01) at 150 minutes and 134.2% (p<0.01) after 180 minutes when compared with the aqueous control. Conclusion: The medicinal plants were found to show potent inhibition of glucose diffusion across the membrane. These results indicate that these plants could quite possibly show hypoglycaemic activity due to this inhibitory action. However, further studies at a molecular level are essential to confirm this mechanism.