A prospective study was conducted from 1977 through 1983, to determine the incidence of complications, particularly bleeding, after fine needle biopsy for suspected malignancy of the abdomen and pelvis. Hematocrits before and after the biopsy procedure, medical record follow-up, and review by a coagulation specialist were used to identify bleeders. We performed 395 biopsies on 360 patients. Thirteen percent of the patients had bothersome pain either during or after the biopsy. Hematocrit drops of 3% or more were found in 51 (12.7%) of the patients; nine were determined to be a direct result of the biopsy procedure. Our results and review of the literature suggest that there are complications, including delayed bleeding, yet few are life threatening. We caution, however, that adequate follow-up to identify bleeders is very important in patients having fine-needle biopsies of solid masses of the abdomen.