AIM:To study the complications and the risk factors of percutaneous liver biopsy, and to compare the complication rate between the periods of 1987-1993 and 1994-1996.METHODS:Medical records of all patients undergoing percutaneous liver biopsy between January 1, 1987 to September 31, 1996 in Songklanagarind Hospital were reviewed retrospectively.RESULTS:There were 484 percutaneous liver biopsies performed. The total complication rate was 6.4%, of which 4.5% were due to major bleeding; the death rate was 1.6%. The important risk factors correlated with bleeding complications and deaths were a platelet count of 70X10(9)/L or less, a prolonged prothrombin time of >3seconds over control, or a prolonged activated partial thromboplastin time of > 10 seconds over control. Although physician inexperience was not statistically significantly associated with bleeding complications and deaths, there was a reduction of death rate from 2.2% in 1987-1993 to 0% in 1993-1996. This reduction is thought to result from both increased experience of senior staff and increased supervision of residents.CONCLUSIONS:Screening of platelet count, prothrombin time, and activated partial thromboplastin time should be done and need to be corrected in case of abnormality before liver biopsy. Percutaneous liver biopsy should be performed or supervised by an expert in gastrointestinal diseases, especially in high risk cases.