Primary Sjögren's syndrome (PSS) is an autoimmune disease of the exocrine glands that is presented with progressive ocular and oral dryness, parotid enlargement and often with systemic (extraglandular) manifestations. In patients with PSS the risk of development of non-Hodgkin's lymphoma (NHL) is 44-fold compared to healthy population. The risk is associated with certain characteristics of the disease's course: recurrent changes in the parotid glands, lymph node enlargement, skin vasculitis, peripheral neuropathy, anemia and lymphopenia. According to the morphologic and phenotypic characteristics, B-cell low-grade lymphomas prevail. This communication presents a 65-year-old woman with PSS who developed a follicular type B-cell NHL 21 years after the autoimmune disease had been diagnosed. The analysis of our case and the literature review summarize the characteristics of the course of PSS, histologic variants, and evolution and prognosis of NHL in this kind of patients.