The aim of this study was to investigate the performance of minor salivary gland biopsy (MSGB), serological and clinical data in diagnosis of primary Sjögren's syndrome (pSS). Retrospective review of 216 patients who underwent minor labial salivary gland biopsy in last 5 years was performed. Results of the patients with diagnosis of pSS were compared with the patients failing to fill the classification criteria of pSS. Two groups did not differ significantly in terms of clinical symptoms and signs except presence of Raynaud's phenomenon. Specificity and positive likelihood ratio of clinical signs in diagnosis of pSS were quiet low. A total of 78.7% of pSS patients had a focus score >or=1 (Chiscolm's score III/IV) while all of the non-SS patients had a focus score <1 (P < 0.001). MSGB has the best predictive value with highest sensitivity and specificity for pSS diagnosis. Serological markers have higher predictive values compared to clinical symptoms and signs. Presence of Raynaud's phenomenon, lymphopenia and/or hypergammaglobulinemia strengthens the probability of pSS in a patient with sicca symptoms.