A randomized trial involving 32 patients, half of whom received the control (saline infusion) and the other half received a continuous infusion of diltiazem (2 mug/kg/min). The diltiazem group had significantly higher creatinine clearance during the pneumoperitoneum than the control group, but both groups equalized their urine output by 2 hours postoperative. This may be a useful treatment to prevent renal damage in patients with renal insufficiency who are undergoing laparoscopic procedures. It might also be useful in improving immediate graft function following laparoscopic donor nephrectomy.