BACKGROUND: Portopulmonary hypertension (PPH) is a severe complication of liver cirrhosis, which poses a high risk for postliver transplantation (LT) mortality. In most liver transplant centers, severe PPH is viewed as an absolute contraindication for LT, but recent reports challenge this. The purpose of our study was to determine the incidence of PPH, its influence on the 30-day mortality rate following LT and to determine the sensitivity and specificity of Doppler echocardiography and electrocardiography as noninvasive tools to determine PPH. METHODS: We studied 74 consecutive patients that underwent LT between February 2004 and November 2005. Pulmonary arterial pressure and cardiac index were repeatedly determined during surgery and postoperatively. PPH was defined as mild (mean pulmonary arterial pressure (MPAP) 25-35 mm Hg), moderate (MPAP of 35-45 mm Hg) and as severe (MPAP >45 mm Hg). RESULTS: The total incidence of PPH was 31% (16 mild, 5 moderate, and 2 severe). There was a tendency towards increased 30-day mortality rate in patients with PPH compared to controls (22% vs. 12%, P=0.1). However, the two patients with the most severe PPH survived. The duration of ventilation and total stay at the intensive care unit did not differ significantly between groups. The positive predictive value of Doppler echocardiography for PPH was 39% and the negative predictive value 90%. CONCLUSIONS: Mild pulmonary hypertension is common in patients with liver failure, whereas moderate and severe hypertension is not. Severe PPH should not be considered as absolute contraindication for LT.