OBJECTIVE To investigate the effectiveness of using continuous veno venous hemofiltration (CVVH) in the treatment of acute necrotizing pancreatitis (ANP). METHODS Thirteen ANP patients were involved in this study, including 4 females and 9 males, averaging 50.6 +/- 10.8 years old. CT scans upon admission revealed 33% necrosis involving the body of the pancreas in 2 patients, 67% necrosis in 3 patients and 100% necrosis in the other 8; the CT severity score was 8.9 +/- 2.1. CVVH was maintained for at least 72 hours and the AN69 hemofilter (1.2 m(2)) was changed every 24 hours. The ultrafiltration rate during CVVH was 2993.9 +/- 983.0 ml/h, the blood flow rate was 250 - 300 ml/min, and the substitute fluid was infused in a pre-diluted manner. Low molecular weight heparin was used as anticoagulant. RESULTS CVVH was well tolerated in all the patients. Bloody abdominal cavity drainage fluid was observed in 2 patients, but no other side-effects related with CVVH were observed. Two patients died of systemic fungal infections and another died of intracranial fungi infection, resulting in an ICU mortality of 23.1%. Ten of the patients survived in the ICU, but one of them died for other reasons unrelated to the SAP before discharge. The APACHE II score before CVVH was 15.2 +/- 6.5, but decreased significantly to 8.1 +/- 5.3, 7.5 +/- 4.9 and 8.0 +/- 5.2 at the 24th, 48th and 72nd hour after CVVH, respectively (P < 0.01). Serum concentration of IL-1beta and TNFalpha decreased to the trough at the 6th hour after a new hemofilter was used and increased slowly to pre-CVVH levels 12 hours later. After CVVH had ceased, the serum levels of two cytokines increased to their peaks at the 120th hour and decreased eventually at the 144th hour. The sieving coefficient (SC) of IL-1beta and TNFalpha was 0.33 +/- 0.11 and 0.16 +/- 0.08. CONCLUSIONS CVVH offered therapeutic options for ANP and was well tolerated resulting in clearance of IL-1beta and TNFalpha; CVVH at early stages of SAP may contribute to the improvement of outcome.