The aim of this study is to define risk factors for severe complications following anatomical liver resections. The study material consists of the first 50 patients (26 women, 24 men, at mean age 50.6 years) treated at 3rd Department of Surgery 2nd Faculty of Medicine, Medical University in Warsaw. The indications for resection included benign neoplasm in 19 cases and malignancy in 31 cases. All the patients underwent anatomical liver resection in accordance with Couinaund's segmental division. In order to define prognostic factors for severe postoperative complications, a multi-factor statistical analysis was conducted. The following parameters were analysed: patient's age, the levels of bilirubin, total protein, albumin, prothrombin time, kaolin-kephalin time, range of resection and blood loss during operation. Eleven patients (22%) died in postoperative period. In 8 cases the death was caused by liver failure. Statistical analysis showed that blood loss, albumin level on fifth postoperative day and kaolin-kephalin time before and after surgery are independent risk factors predisposing to the development of complications.