Introduction. Sj?gren?s syndrome (SS) is an autoimmune disease of unknown etiology, clinically manifested by dry eyes (xerophthalmia) and dry mouth (xerostomia). In childhood SS is a rare disease, clinically atypically or asymptomatic and is often unrecognized. We report a girl with asymptomatic, juvenile form of primary Sj?gren?s syndrome (JSS). Case Outline. A 13?year?old girl was initially observed for several months due to elevated sedimentation rate (ESR 75?90 mm/h) without signs of inflammation or other symptoms and disease signs. Subjective symptoms of dryness of the eyes and mouth were absent at the beginning. Ophthalmologic examination demonstrated hypolacrimia although the patients had no subjective signs of xerophthalmia. Ultrasonography (US) revealed mild enlargement and heterogeneity of large salivary glands parenchyma. Increased rheumatoid factor (RF), anti SS?A/Ro, anti SS?B/La antibodies were found in serum. Ophthalmologic examination demonstrated decreased lacrimation. JSS was confirmed on the basis of ophthalmologic examination, immunological tests, histological findings of biopsy of small and US of major salivary glands. During a 12?years follow?up period systemic or extraglandular manifestations of JSS and other autoimmune diseases were not observed. Conclusion. Our experience suggests that in the differential diagnosis of unexplained elevated ESR the primary form of JSS should be also taken into consideration. Ultrasonographic changes of major salivary glands in the absence of symptoms of xerostomia point out that this noninvasive method has an important role in the diagnosis and management of patients with JSS.