Radioimmunotherapy (RIT) was approved for the treatment of relapsed or refractory CD20-positive follicular lymphoma (FL), subsequent to rituximab containing primary therapy. However, an increasing number of clinical studies have suggested that RIT may be more efficacious in an earlier phase of the disease. Therefore, a consensus meeting was held in May 2005 to define the optimal setting of RIT in the therapeutic algorithm of patients with advanced stage of FL. RIT is an established therapeutic option in relapsed FL. According to the reviewed data, RIT should be preferably used as consolidation after initial tumor debulking. First-line RIT may be applied in patients not appropriate for chemotherapy induction. Current study concepts evaluate the role of RIT consolidation in combination with antibody maintenance to achieve a potentially curative approach even in patients with advanced stage disease.