OBJECTIVES: 90Y Ibritumomab Tiuxetan has been recently approved in the European Union as consolidation therapy after remission induction in previously untreated patients with B-cell Non-Hodgkin’s Lymphoma (NHL). As a result, the objective of the present study was to compare its treatment costs vs. Rituximab maintenance ones in Spain. METHODS: A microcosting exercise was performed with Microsoft Excel considering Spanish medication and premedication costs for both therapeutic alternatives. Also administration costs were considered. The perspective for cost calculation was that of the National Health System. Drug costs were obtained from IMS, posology was derived from drug technical specifications and premedication patterns were assessed by expert opinion. Other costs were obtained from specialized sources. Costs were expressed in euros 2008. No discounting was needed. The schema of the PRIMA study was considered to determine Rituximab maintenance administration pattern. It was taken into account that 250 mg/m2 of Rituximab are administered twice, previous to 90Y Ibritumomab Tiuxetan consolidation, as premedication. RESULTS: 90Y Ibritumomab Tiuxetan consolidation represented a 32% reduction in treatment costs with respect to Rituximab maintenance for hospitals in Spain. Absolute figures accounting for medication, premedication, drug preparation and administration costs for both therapeutic options were €15,675 for 90Y Ibritumomab Tiuxetan consolidation and €22,934 for Rituximab maintenance. If we accounted only for drug costs, absolute figures were: €15,203 for 90Y Ibritumomab Tiuxetan and €21,044 for Rituximab. Regarding premedication costs, 16% of 90Y Ibritumomab Tiuxetan consolidation costs were due to premedication administered, which is mainly Rituximab and its premedication, paracetamol and diphenhydramine. CONCLUSIONS: 90Y Ibritumomab Tiuxetan consolidation administered once post-chemotherapy in previously untreated patients with B-cell NHL is less costly than Rituximab maintenance administered every two months for two years in Spain.