[en] Neuroendocrine tumours are neoplasms that arise from various tissues closely linked to the neural crest by their common embryological origin. These tumours have the ability to synthesize neurotransmitter peptides and hormones, as well as to store catecholamines. Some of these tumours express somatostatin receptors at their membranes, what have allowed nuclear medicine to be involved in their diagnosis, treatment and monitoring. Since they arise from different and varied types of tissues, these tumours have a wide range of signs and symptoms different for every one of them. These signs and symptoms mainly depend on their biochemical characteristics, given by the substances they secrete, as well as by their location, and consequently, they also depend on the place where the tumour appears, its local infiltration, and potential long-distance metastasis resulting from the tumour). Neuroendocrine tumours are diagnosed by means of nuclear medicine images, which are obtained by using different techniques and radiopharmaceuticals such as ⁹⁹mTc dimercaptosuccinic acid (DMSA(V)), ⁹⁹mTc-methoxy-isobutyl-isonitrile (MIBI), metaiodobenzylguanidine (MIBG) labelled with ¹³¹I or ¹²³I (¹³¹I-MIBG or ¹²³I -MIBG), ¹¹¹In-labelled octreotide, positron emission tomography, using ⁶⁸Ga-labelled somatostatin analogues and carcinoembryonic antigen monoclonal antibodies. Nuclear medicine uses mainly somatostatin analogues labelled with ⁹⁰Y or ¹⁷⁷Lu for the treatment of these tumours. This paper is aimed at showing our experience in the use of ¹³¹I-MIBG for the diagnosis and treatment of neuroendocrine tumours.(author)