Pentoxifylline is a safe and well-tolerated methylxanthine derivative with several pharmacological properties that made a well-established therapy for the treatment of intermittent claudication associated with peripheral vascular diseases. It can reduce blood and plasma viscosity, and plasma fibrinogen while promoting fibrinolysis. It can improve blood filterability by enhancing erythrocyte distensibility and reduce neutrophil activation. Pentoxifylline also has anti-inflammatory effects and was reported to have the potential for retarding the progression of atherosclerosis. The aim of this book is to describe pentoxifylline research progress in various fields of medicine including nephrology, cardiology, andrology, hepatology, neuropsychiatry, pulmonology, and ophthalmology.