Objective: Allium hirtifolium (Persian shallot) has a hypoglycemic effect on diabetic animals. The aim of this study was to assess the effect of the ethyl acetate fraction of Allium hirtifolium on the function of isolated hearts of diabetic rats. Materials and Methods: The control and diabetic animals were randomly divided into four groups: saline- or extract-treated controls (n=10 and n=6, respectively) and saline- or extract-treated diabetic rats (n=8 and n=9, respectively), which received normal saline or extract for four weeks by daily gavage. The hearts were perfused according to the Langendorff method. Cardiac function parameters, including left ventricular developed pressure (LVDP), heart rate (HR), rate pressure product (RPP; LVDP×HR), and dp/dt were measured. Results: The findings of this study showed that in the extract-treated diabetic rats, LVDP (94.5±9.1 mm Hg, mean±SEM), HR (249±15 beats/min), RPP (22732±1246) and +dp/dt (2598±230) at the baseline were significantly higher than those in the saline-treated diabetic animals, (71.5±4.0), (189±6), (13923±984), and (1701±124), respectively. Furthermore, RPP and HR were also significantly higher than the corresponding values obtained in the saline-treated diabetic rats after ischemia. Conclusion: Besides blood glucose lowering action, oral administration of the ethyl acetate fraction of Allium hirtifolium significantly improved the baseline and post-ischemic cardiac function parameters in streptozotocin-induced diabetic rats.