Radioimmunotherapy (RIT) with (90)Y-ibritumomab tiuxetan or (131)I-tositumomab combines a radiation-emitting radionuclide with an antibody targeting CD20 to treat B-cell non-Hodgkin lymphoma. Multiple studies demonstrate favorable RIT efficacy and safety profiles in follicular lymphoma (FL). The primary toxicity is reversible myelosuppression. Various FL treatment options include single-agent immunotherapy, radiation, chemoimmunotherapy, and RIT. Examining RIT clinical effects and position within treatment algorithms is important to optimal patient benefit. Clinical studies support using single-agent RIT in relapsed/refractory FL, in selected patients with new, untreated FL, and as consolidation after induction chemotherapy or chemoimmunotherapy. RIT as consolidation enhances response rates (with conversion of partial to complete responses following induction therapy) and prolongs disease control versus observation. The overall response rate is 60-80% in the relapsed setting. Time to progression is longer with low-bulk disease, fewer prior therapies, and retained rituximab sensitivity. RIT apparently does not preclude subsequent therapies or increase risk of secondary malignancies compared with chemotherapy's known risk. This article summarizes consensus recommendations for RIT and presents RIT treatment algorithms developed by hematologists/oncologists who regularly treat patients with FL. Maximizing RIT benefit requires healthcare providers to utilize algorithms assisting with treatment decisions.