Abstract: Increased oxidative stress plays a role in the pathogenesis of cellular death and β-cell failure. The aim of this study was to evaluate the action of different types of phosphodiesterase (PDE) inhibitors including milrinone (PDE-3), rolipram (PDE-4) and sildenafil (PDE-5) on viability, production of Reactive Oxygen Species (ROS) and secretion of insulin from isolated rat pancreatic islets. Pancreatic islets were carefully isolated and incubated in RPMI 1640 for 24 h. After overnight incubation, islets were picked up and divided into ten in each groups. Then, milrinone, rolipram and sildenafil at doses of 0.1, 1, 10 and 100 FM were added to islet groups and incubated for further 24 h. Then static insulin secretion at 2.8 and 16.7 mM concentrations of glucose, was tested. Then the viability of cells, level of ROS and insulin were examined. The results of static experiments showed that secretion of insulin increased significantly in response to glucose at both basic (2.8 mM) and stimulation (16.7 mM) levels by the lower doses of tested PDE inhibitors. The level of ROS at the lower doses of milrinone decreased. The viability of islets at the lower doses of all of PDE inhibitors were increased; however, viability at the higher doses of sildenafil and rolipram reduced significantly. Milrinone was the most effective PDE inhibitors on the function of isolated pancreatic islets. PDE inhibitors show the most significant anti-oxidative effects at lower doses. Concerning improvement of isolated islets function, PDE-3 inhibitor is the best among tested compounds. PDE inhibitors may help management of diabetes and facilitate conditions of islet transplantation.