[en] Aim: Immunoscintigraphy (IS) and intraoperative radioimmunodetection with hand-held gammaprobe (radioimmunoguided surgery, RIGS) can add important information about location and extent of colorectal cancer. Apart from the correct technique of IS and RIGS, the choice of proper radiopharmaceutical is important. The aim of this study was compared results with two radiopharmaceuticals. Material and Methods: 127 patients with known or suspected colorectal cancer were studied, 58 patients with 111In-satumomab (Oncoscint) and 69 patients with 99mTc-arcitumomab (CEA-Scan). IS and RIGS were performed in all of the patients. In 123 patients colorectal cancer was verified by postoperative histology. IS with Oncoscint was being performed as the whole body scan and SPECT of abdomen within 2-3 and 3-4 days after injection. RIGS was carried out 4-7 days after injection. IS with CEA-Scan was being performed as the whole body scan and SPECT of abdomen within 3-5 hours and planar scintigraphy 21-23 hours after injection. RIGS followed on the same day. After operation the counts of resected tissues were measured and suspected tissues were examined by histology. The ratio of the activity of tumor and healthy tissue was determined both intraoperatively and postoperatively. Results: The sensitivity of IS in primary tumor or local recurrence was 93% with Oncoscint and 92.5% with CEA-Scan, the accuracy 91% in both the radiopharmaceuticals. In extrahepatic metastases the sensitivity was 50% and accuracy 67% with Oncoscint, 57% and 78% with CEA-Scan. In hepatic metastases the sensitivity was 79% and accuracy 95% with Oncoscint, 75% and 93% with CEA-Scan. Primary malignant tumor or local recurrence was detected intraoperatively in 98% with Oncoscint and 100% with CEA-Scan, extrahepatic metastases in 75% with Oncoscint and 83% with CEA-Scan. The activity ratio of malignant tumor to healthy tissue was intraoperatively 1.1-5.0 with Oncoscint and 1.6-10.1 with CEA-Scan, postoperatively 1.3-4.8 and 1.8-8.5. Conclusion: The results with the both different monoclonal antibodies are similar in immunoscintigraphy and also in RIGS. The statistical analysis of our study shows no significant differences between the two radiopharmaceuticals