The role of laparoscopy and thoracoscopy as diagnostic modalities in blunt and penetrating abdominal trauma was studied in 35 hemodynamically stable patients who otherwise would have undergone exploratory laparotomy because of equivocal diagnostic findings. Minimally invasive laparoscopic techniques (single 5 millimeter port) and minimal abdominal insufflation (8-10 millimeters mercury) were used with general anesthesia. Both laparoscopy and thoracoscopy appear to be safe (no complications), highly sensitive (100%), specific (88%), and accurate (91%) tools for determining the presence of surgically significant abdominal pathology and the need for therapeutic laparotomy. The appropriate application of these techniques, possibly under local anesthesia, offers potential cost savings.