Aims: We evaluated the response and toxicity, after long-term follow up of Iodine-131 rituximab radioimmunotherapy in patients with follicular lymphoma under the routine clinical care of a single hematologist over a period of 12 years. Materials and methods:Patients received 131 I-rituximab radioimmunotherapy according to a standard, personalized dosimetry protocol predicated upon a prescribed whole body radiation absorbed dose of 0.75Gy. Four doses of maintenance rituximab were subsequently administered over 12 months. Results:Response rate was 97% with 24(77%) patients experiencing a complete remission confirmed on 18 Ffluorodeoxyglucose positron emission tomography-computerized tomography scan. The cohort of 3 patients with duodenal lymphoma all achieved complete remission lasting 4-5 years. Disclosure statement:There is no conflict of interest to declare with the publication of this work. No author has a financial incentive associated with the publication of this article. Conclusion:131 I-rituximab radioimmunotherapy is an effective, safe, affordable, repeatable treatment which does not compromise future therapy options upon relapse. It is practical, being administered on an outpatient basis, and referring physicians maintain governance of their patients.