The aim of this study was to analyze the outcomes of 37 follicular lymphoma (FL) patients treated with (90)ytrium ibritumomab tiuxetan (90Y-IT), outside of clinical trial, according to protocol ISCRTN36210045, after ≥5 years follow-up to February 2014. Health-related quality of life (HRQoL) was evaluated with the SF-36, Spanish version, and compared with the general population of Spain. Patients had a mean age of 61.9 (range, 30-85) years and included 18 males. FLIPI, low: 25 (67.6 %), intermedium 9 (24.3 %), and low 3 (8.1 %). Previous therapy schedules >2: 48.6 % The median follow-up was 66 months, mean Time to Relapse (TTR) 71.3 months (58.8-83.8) median not reached. Thirty-four patients achieved complete response (91.8 %), and three no response. Mean overall survival: 82.3 months (71.6-92.9). Four patients presented with concomitant tumors (colon, breast, prostate, lung) after radioimmunotherapy, and three developed second primary neoplasms (esophagus, renal, and myelodysplastic syndrome in a relapsed patient who received fludarabine). Four of 10 deaths were related to lymphoma progression. Hematological toxicities were mild and easily managed. No patients required hospitalization. Negative scores were obtained in the physical and emotional roles items; however, the perception of general health and vitality were better than in the general population, with the best outcomes in non-relapsed patients. Radioimmunotherapy with 90Y-IT was safe and effective as long-term therapy in patients with FL. Early use of radioimmunotherapy could offer good, sustained responses with low toxicity over the long term and acceptable HRQoL.