Staging laparoscopy avoids unnecessary laparotomies in patients with unresectable intra-abdominal malignancies. However, the postoperative oncologic treatment of these patients has not been documented. This study compares rates and timing of postoperative chemotherapy (ChT) and/or radiation therapy (XRT) in patients with unresectable intra-abdominal malignancies initially evaluated by staging laparoscopy (SL) or exploratory laparotomy (EL). The records of patients surgically evaluated for esophageal, gastric, hepatobiliary, and pancreatic cancers or abdominal lymphoma were retrospectively reviewed. Data gathered included type of exploration (SL or EL), resectability, whether postoperative cancer treatment was given (ChT, XRT, or both), and the time from surgery to the beginning of such treatment. This study includes only patients with unresectable malignancies. Twenty-one patients underwent SL and 58 EL. Sixteen of the SL patients (76%) and 25 of the EL patients (43%) received postoperative cancer treatment (P = 0.009). The median number of days from surgery to postoperative cancer treatment was 13 days (range 5 to 41 days) for the SL group and 35 days (range 16 to 89 days) for the EL group (P = 0.0004). We conclude that patients with unresectable intra-abdominal malignancies discovered by SL are more likely to receive postoperative ChT and/or XRT than patients surgically evaluated by EL. Further studies to determine whether this better utilization of postoperative treatment results in better outcomes in these patients are needed.