A 55-year-old woman presented with a 3-month history of severe transfusion-dependent anemia. Physical examination revealed pale skin but no hepatosplenomegaly or lymphadenopathy. A complete blood count showed normocytic anemia (4.6 g/dL; mean cell volume, 90 fL) with reticulocytopenia (3 × 10 9/L) and normal leukocyte and platelet counts. Bone marrow smears (panel A) and biopsy specimen (panel B) showed extensive infiltration (65%) by CD20 + CD5 + CD23 − cyclin D1 + lymphoid cells, with a marked reduction of erythroblasts (1%). Cytogenetics analysis revealed a complex karyotype with t(11;14). Parvovirus B19 serology was negative, as was the polymerase chain reaction performed on bone marrow. The patient was diagnosed with mantle cell lymphoma (MCL) complicated by pure red cell aplasia (PRCA). Cytarabine-based chemotherapy combined with rituximab led to rapid transfusion independency and complete disappearance of bone marrow infiltration (panel C, cyclin D1 expression before treatment; panel D, glycophorin expression after treatment).PRCA is a rare disorder, defined by the presence of severe normocytic anemia, reticulocytopenia, and a profound reduction of the bone marrow erythroid precursors. Its association with lymphoproliferative disorders is infrequent, mainly described with T-cell large granular lymphocyte leukemia, angioimmunoblastic T-cell lymphoma, chronic lymphocytic leukemia, diffuse large B-cell lymphoma, and follicular lymphoma. Only 1 case of PRCA associated with MCL has been described so far, also presenting in a nonnodal form of MCL but occurring later in the course of the disease and responding only to immunosuppressive therapy.