Diabetes impairs the expression and function of endogenous growth factors, leading to increased cardiovascular events in diabetic patients. Supplementation of fibroblast growth factors (FGFs) protected the heart from ischemia/reperfusion (I/R)-induced injury in animal models. However, it has not yet been tested in diabetic heart. The present study was thus to clarify whether basic fibroblast growth factor (bFGF) could protect the heart from I/R-induced damage under diabetic conditions using a rat model. Male Sprague Dawley rats were used to induce diabetes by intraperitoneal injection of streptozotocin. Eight weeks later, I/R injury was generated in diabetic rats and age-matched non-diabetic rats. All I/R rats were administrated bFGF or saline through intramyocardial injection. Seven days after I/R, cardiac infarction, structural changes, cell death and blood vessel density, serum malondialdehyde (MDA) and cardiac enzyme lactate dehydrogenase (LDH) were examined. We found that I/R induced significant increases in the cardiac infarction, blood MDA contents and LDH activities, and the expression of caspase-3. Treatment of I/R rats with bFGF simultaneously with reperfusion significantly attenuated I/R-induced pathological changes, along with a significant increase in the cardiac blood vessel density in both diabetic and non-diabetic rates. The protective effects of bFGF on I/R-induced cardiac injury in diabetic group are less than those in non-diabetic group. The results indicated that bFGF provide a protection of the heart against I/R-induced oxidative damage, cell death and infarction under diabetic conditions.