OBJECTIVE To prospectively compare the speed, sensitivity, complications, and technical failures of percutaneous diagnostic peritoneal lavage (DPL) using a Veress needle versus open DPL. METHODS One hundred seventy-six blunt trauma patients requiring DPL were prospectively randomized to undergo either open DPL using a standard technique or percutaneous DPL using an 18-gauge Veress needle to penetrate the peritoneal cavity, with the lavage catheter then being inserted over a guide wire. RESULTS Mean time to successful placement of the lavage catheter for the percutaneous Veress needle technique was 2.73 minutes versus 7.28 minutes for the open DPL technique (p < 0.001). Sixteen percent of open lavage procedures took more than 11 minutes; the majority (60%) of Veress needle lavage procedures took less than 2 minutes. There were no false-negative findings in either group, and there was one false-positive result in each group. A wound infection after an open DPL was the only complication. Poor return of lavage fluid (<200 mL) accounted for most technical failures; this was more prevalent with the percutaneous method (11.2%) than with the open technique (3.8%) (p < 0.05). CONCLUSIONS The percutaneous DPL method using a Veress needle is significantly faster than the open DPL method. The Veress needle lavage was as safe and as sensitive as the open lavage; however, technical failure occurred more frequently with the Veress needle lavage than with the open DPL.