Sjogren's syndrome is a systemic autoimmune disease characterized by sicca symptoms and B lymphocyte hyperactivity. Hematological abnormalities are common in Sjogren's syndrome, including anemia, leukopenia, thrombocytopenia, and lymphoproliferative disorders. These hematologic involvements are mostly recognized as mild laboratory abnormalities. Life-threatening, severe thrombocytopenia is very rare. We describe a patient with primary Sjogren's syndrome, who developed very severe thrombocytopenia during the clinical course and successfully treated with high dose dexamethasone therapy.