The role of the nuclear medicine department in the diagnosis and management of malignant disease is constantly evolving. For example, the development of new radiopharmaceuticals, such as indium-111-labelled octreotide (pentetreotide), has enabled more specific imaging for the diagnosis of gastroentero-pancreatic (GEP) endocrine tumours to be carried out. New techniques such as sentinel lymph node localisation and biopsy now allow less invasive tumour staging. Advances in chemotherapy necessitate careful monitoring of the effects of chemotherapeutic drugs on normal organ function during follow-up, and tumour specific radiopharmaceuticals are being used for non-invasive, targeted tumour therapy. Nuclear medicine investigations should always be interpreted in the knowledge of results of other imaging investigations if they are to have greatest impact on patient care.