Pulmonary complications, mainly hepatopulmonary syndrome (HPS), are frequently observed in liver cirrhosis. In this study, the aim was to investigate the frequency of hypoxemia and impairment of pulmonary function tests (PFT) in patients with liver cirrhosis and to examine the relationships of these impairments with liver failure. A total of 39 patients with cirrhosis, 24 males and 15 females, were included in our study. The mean age of the patients was 47.5 +/- 17.2 years. Arterial blood gases, PFT, and carbon monoxide diffusion tests (DLCO) were performed in all patients. Out of 39 cirrhotic patients, 21 (53.8%) had ascites, whereas 18 (46.2%) did not. Seven patients were in the Child-Pugh A group, 21 in the Child-Pugh B group, and 11 patients were in the Child-Pugh C group. Hypoxia was found in 33.3% of the patients. Although the PaO2 and SaO(2) values of patients with ascites were lower compared to those without ascites (P < 0.05), no statistically significant difference was determined in the comparison of hypoxia between the groups (P > 0.05). Among the PFT parameters, FEV1/FVC and FEF25-75% values were found to be lower in patients with ascites than those without (P < 0.05). No differences were established between these two groups of patients in terms of DLCO (P > 0.05). While no differences were found in comparison of the DLCO values in between the groups (P > 0.05), there was a statistically significant difference in the ratio of DLCO to the alveolar ventilation (DLCO/VA) in between the groups (P < 0.05). On the other hand, a negative correlation was found between the DLCO/VA and Child points when the relationship between the Child-Pugh score and PFT parameters were investigated (r = -0.371, P < 0.05). Consequently, a relationship was established between the severity of liver failure and diffusion tests showing pulmonary complications invasively. We believe diffusions tests should be performed in addition to the PFT in order to determine pulmonary involvements particularly in patients who are candidates for liver transplantation.