Objective: The objective of this study was to determine the acute toxicity and antidiabetic activity of the methanolic extract of Hygrophila auriculata in adult male Wistar rats. Methods: Methanolic extract was prepared by optimized maceration procedures. Then, they were administered to groups of six rats in doses of 0, 100, 500, 750, 1000 and 3000 mg/kg body weight. The rats were then observed for signs of acute toxicity and these were duly recorded. Other parameters tested were Chloride and Calcium levels, Alkaline Phosphatase Levels and α-amylase levels. Results: The methanolic extract was found to show no oral toxicity even at the highest dose of 3000 mg/kg body weight. Moreover, it was an effective antidiabetic agent at concentrations as low as 10mg/kg body weight. Conclusion: The present study shows that the methanolic extract of H. auriculata is non-toxic when administered orally even at higher concentrations. © 2015, Pharmainfo Publications. All rights reserved.