Pulmonary hypertension (PH) leading to right ventricular failure (RVF) is a common complication of left heart failure irrespective of the left ventricular ejection fraction. PH due to left heart disease is the most common cause of PH. The prevalence of PH and RVF in left heart failure varies depending on the patient population studied, the method used to diagnose PH, and the hemodynamic criteria used to define PH. Elevated left-sided filling pressure and functional mitral regurgitation are the two major determinants of PH in left heart failure. PH is associated with markers of disease severity, advanced symptoms, and worse long-term outcomes including heart failure hospitalization and mortality in left heart failure. RVF has independent, incremental prognostic value over PH for adverse outcomes in left heart failure. PH and RVF may be potential therapeutic targets in patients with left heart failure.