Normal as well as activated lymphocytes, macrophages and leukaemic cells have previously been shown by radio receptor analysis to express receptors for somatostatin. An 111In labelled somatostatin analogue was already used successfully in the visualization of a variety of neuro-endocrine tumours. We investigated 10 consecutive patients with malignant lymphomas (Hodgkin's disease and non-Hodgkin's lymphomas). In all patients the lymphoma deposits could be visualized with somatostatin receptor imaging. In four patients additional tumour localizations were observed as compared to the results of combined physical and radiological (CT and ultrasound) examinations. In four cases tissue biopsies were taken and confirmed by autoradiography to be somatostatin receptor positive. These data indicate that malignant lymphomas may express somatostatin receptors in sufficient numbers and density to allow in vivo tumour visualization with a radiolabelled somatostatin analogue.