Pulmonary hypertension (PH) is a relatively common hemodynamic finding in patients with left-sided heart disease and is usually associated with increased morbidity and mortality. However, so far no study has demonstrated long-term benefit from drugs specifically designed to improve pulmonary hemodynamics. There are currently no consensus recommendations on the management of PH in patients with chronic left heart failure. Most importantly, the underlying cause of left heart disease should be treated first. While previous studies with endothelin receptor antagonists or epoprostenol have been disappointing, initial promising results have been published for the phosphodiesterase-5 inhibitor sildenafil. Following acute administration and with chronic therapy for up to 6 months sildenafil improved hemodynamic parameters and exercise capacity in patients with PH and chronic left heart failure. Until the results from larger randomized controlled trials become available, the treatment of chronic left heart failure should follow the current guidelines.