Sjögren's syndrome is one of the most frequent autoimmune diseases. It is a chronic and systemic disorder predominantly found in women, and is characterized by the appearance of a lymphocytic inflammatory infiltrate, with dryness of the oral cavity and eyes, secondary to involvement of the salivary and lacrimal glands. The underlying causal mechanism involves a number of factors and has not been clearly established, though an autoimmune response is known to be triggered, with the accumulation of immune complexes in the gland acini that interfere with gland function. In the oral cavity, xerostomia or hyposialia is the most disabling manifestation for patients, and is accompanied by rapidly progressing caries, candidiasis and an important worsening of buccodental health. The most important complication is a 44-fold increase in the risk of developing non-Hodgkin lymphoma, compared with the general population. The treatment of Sjögren's syndrome is limited to symptomatic management, and involves the use of solutions to replace salivary secretion and afford a measure of hydration, cholinergic agents such as pilocarpine to stimulate the unaffected gland tissue and, recently, the administration of substances that act against surface antigens of the B lymphocytes, such as anti-CD20 and anti-CD22 antibodies. The present study provides an update on this disease, placing special emphasis on its odontologic implications.