Tumour associated monoclonal antibodies HMFG1, HMFG2, H17E2, AUA1, EGFR1, labelled with 123-Iodine or 111-Indium, were used to detect primary and metastatic cancer by external body scintigraphy in patients with ovarian, breast and non-small cell lung cancer (NSCC). Successful localisation was seen in all patients with primary and 80% of the metastatic NSCC, 50% of primary and 70% of metastatic breast cancer lesions and in 80% of patients with metastatic ovarian cancer. On the other hand, imaging carried with a radiolabelled non-specific monoclonal antibody produced positive results in 3 out of 5 cases with primary NSCC. Therefore non-specific imaging should be further studied in clinical research for the evaluation of the specificity of radioimmunodetection. In our therapeutic trials we have so far treated 29 patients with resistant ovarian cancer, with intraperitoneal 131I-labelled antibodies (HMFG1, HMFG2, AUA1, H17E2), 11 patients with recurrent pleural and pericardial effusions by intracavitary 131I-labelled antibodies, 10 patients with brain gliomas by intravenous or intracarotid infusion of 131I-EGFR1 and two patients with hepatic metastases from colon carcinoma by intrahepatic infusion of 131I-anti-CEA antibodies. The preliminary results from these therapeutic studies seem to be encouraging and are discussed in detail in this review.