There is no adequate data in the medical literature defining serum CA-125 levels after laparoscopy. Therefore we designed this prospective study to evaluate the effects of laparoscopy on serum CA-125 levels. Eighty-two women (mean age 34.2 +/- 12.30 years) were included in the study between January, 2001 and April, 2003. Laparoscopies were performed in patients with chronic pelvic pain, dysmenorrhea, infertility, ovarian cysts and for tubal ligation. Mean serum CA-125 levels of the patients before and after the laparoscopic procedures were 13.96 +/- 4.86 U/ml and 14.02 +/- 4.96 U/ml, respectively. The change in serum CA-125 levels prior to laparoscopy was statistically insignificant when compared with the levels obtained at 24 hours after laparoscopic procedure (p > 0.05). We found that diagnostic laparoscopy or laparoscopic surgical procedures did not change the levels of CA-125 at the 24th hour after laparoscopy indicating either serum CA-125 levels are not correlated, at least within 24 hours, with peritoneal irritation or peritoneal irritation is minimal or absent in our operations.