A rapid and simple method for ascites concentration and reinfusion was utilized to treat 103 episodes of tense ascites in 57 patients (38 men and 19 women, mean age 63 +/- 11 years). After a bedside total paracentesis, 6.06 +/- 2.87 liters of ascites were separately ultrafiltrated using a mechanical device during a mean interval of 134 +/- 88 min, and 430 +/- 368 ml of concentrate containing 39 +/- 42 g of albumin were restituted at bedside either intravenously (44 cases) or intraperitoneally (59 cases). Ultrafiltration was successfully and easily completed in all cases. Ascites concentration and reinfusion either intravenously or intraperitoneally did not adversely modify hemodynamic or renal parameters except for a transient decrease in mean arterial pressure (P < 0.05). Transitory hyponatremia and renal failure occurred in two patients. A transient decrease in platelet count and serum fibrinogen levels (P < 0.05) and pyrexia (12%) were observed only in patients reinfused intravenously. In conclusion, this new method for ascites concentration and reinfusion was effective, safe, and, with respect to traditional methods, simpler, faster and more comfortable. Therefore it is proposed for the routine management of tense ascites.