Therapy with radiolabelled somatostatin analogue peptides is a promising new therapy to treat neuroendocrine tumours. The aim of this preliminary study is to present our experience with Lu-177-DOTATATE therapy, and evaluate tolerability and short-term efficacy in patients with tumours expressing somatostatin receptors. A total of 7 patients with metastatic neuroendocrine tumours were treated, each with 4 doses of mLu-DOTATATE. The treatment response was evaluated in the form of biochemical response (tumour markers), imaging methods (somatostatin receptor scintigraphy, computed tomography, and magnetic resonance), and functional and quality of life responses using the Karnofsky performance status scale. Treatment toxicity was also evaluated. The results obtained were as follows: Biochemical response: 60% of patients showed tumour marker levels returning to normal, while they decreased significantly in the remaining 40%. Imaging response: 85.7% had a partial response, while 14.3% showed stable disease. All (100%) patients showed a significant improvement in quality of life, with increased Karnofsky scale scores. No patient had acute or chronic toxicity, and subacute transient haematological toxicity was observed in 42.8% of patients. Despite being a preliminary study, it was found that treatment with Lu-177-DOTATATE is a safe treatment with few side effects, and an objective response was achieved in most patients. (C) 2016 Elsevier Espaiia, S.L.U. y SEMNIM. All rights reserved.