The present study was undertaken to investigate the antidiabetic activity of extracts of Sida spinosa in alloxan induced diabetic rats by reducing oxidative stress. Diabetes was induced by alloxan (120 mg/kg, i.p.) in albino wistar rats. Diabetes was confirmed by estimating the blood glucose level after 48 hr of alloxan induction. Rats with 200 mg/dl and above blood glucose were considered as diabetic. Selected rats were treated with methanolic (MEE) and water (WTE) extracts of Sida spinosa (150 mg/kg and 300 mg/kg, p.o.) for 21 days. After treatment protocol different biochemical parameters were observed like glucose, triglycerides, creatinine, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline transferase (ALP), urea, total protein and albumin (Alb) was also determined. Even the level of oxidative stress parameters were observed in pancreas like SOD, LPO, GSH and Catalase. MEE and WTE treated group lowers blood glucose level significantly (p<0.01) after 21 days of administration in diabetic rats. These extracts treated group also maintain the biochemical parameters like glucose, triglycerides, creatinine, SGOT, SGPT, ALP, urea, total protein and Alb significantly compared to diabetic rats. It was also observed that in drug treated group significant (p<0.01) reduction in oxidative stress parameters in pancreatic tissue of diabetic rats. The present study concludes that MEE and WTE leaves extract of Sida spinosa showing anti diabetic activity by reducing oxidative stress parameters.