Pure red cell aplasia (PRCA) is an acute anemia due to selective suppression of erythropoiesis. We report a case of PRCA diagnosed before the onset of primary Sjögren's syndrome (SS). A young woman, with autoimmune thyroiditis, developed polyarthritis with ANA and Rheumatoid factor positivity, diagnosed as Rheumatoid arthritis. During the time she developed anti-Ro and anti-La antibodies and deformities at proximal interphalangeal joints. After 4 years, she developed severe acute anemia, without reticolocytes: a bone marrow biopsy indicated a PRCA and she started transfusions, steroids, cyclosporin. A steroid-dependent anemia persisted. After 2 years she developed sicca, parotid swelling, fatigue, mild leukopenia, elevated serum creatinine, hypokalemia, hyposthenuria and tubular proteinuria. Lip biopsy and dacriologic tests confirmed a diagnosis of SS, while X-ray revealed a deforming non-erosive arthropathy (Jaccoud type). In present case, PRCA could be considered an autoimmune bone marrow disease within SS, whose extra-glandular manifestations onset before the sicca symptoms.