BACKGROUND: The identification of all sites of intra-abdominal adenocarcinoma is key to optimal surgical resection and tumor staging. Conventional imaging methods and direct visualization and palpation have limited sensitivity and specificity. Radioimmunoguided surgery (RIGS) has a potential to improve these parameters. METHODS: The development of the RIGS concept is presented, and the studies of tumor localization, detection of disseminated disease, staging, and survival are correlated with the tumor biopsy of gastrointestinal carcinoma, particularly colorectal carcinoma. RESULTS: RIGS can detect clinically and histologically occult neoplasm. Also, by providing immediate intraoperative information, the RIGS approach improves surgical staging, impacts on surgical and medical care, and affects patient prognosis. CONCLUSIONS: RIGS may become the standard of care for the surgical staging and treatment of colorectal cancer and other gastrointestinal malignancies.