Sjögren's syndrome (SS) is a chronic inflammatory disorder of hitherto unknown origin. The characteristic hallmark of SS is focal lymphocytic infiltration and slow destruction of exocrine glands, such as lacrimal and salivary glands. Sicca symptoms and/or recurrent parotid gland swelling are often accompanied by fatigue. Clinically relevant extraglandular manifestations occur in more than 20% of patients with primary SS. The development of malignant B cell lymphoma is the most important complication, which affects about 5% of primary SS patients who are at higher risk to develop malignant B cell lymphoma, both when compared with the general population as well as with patients with SS secondary to other systemic autoimmune disorders. Treatment of sicca symptoms is primarily symptomatic, whereas glucocorticoids, NSAIDs and/or immunosuppressive drugs may be indicated for the treatment of extraglandular manifestations. New therapeutic strategies, such as B cell targeted therapies, are in clinical testing especially for patients with severe organ manifestations.