Objectives to assess the effect of sialendoscopy of the major salivary glands on salivary flow and xerostomia in patients with Sjögren’s syndrome (SS). Methods Forty-nine patients with SS were randomly assigned to a control group (n=15) and two intervention groups: irrigation of the major glands with saline (n=16) or with saline followed by triamcinolone acetonide (tA) in saline (n=18). Unstimulated whole saliva flow (UWS), chewing-stimulated whole saliva flow (SWS), citric acid-stimulated parotid flow (SpF), Clinical oral dryness Score (CodS), xerostomia Inventory (xI) score and the European League Against rheumatism (EULAr) SS patient-reported Index (ESSprI) were obtained 1 week (t0) before, and 1 (t1), 8 (t8), 16 (t16) and 24 (t24) weeks after sialendoscopy. results Median baseline UWS, SWS and SpF scores were 0.14, 0.46 and 0.22 mL/min, respectively. After intervention, significant increases in UWS and SWS were observed in the saline group (at t8 (p=0.013) and t24 (p=0.004)) and the saline/tA group (at t24 (p=0.03) and t=16 (p=0.035)). SpF was increased significantly in the saline/tA group at t24 (p=0.03). xI scores declined after sialendoscopy in both intervention groups. Compared with the control group, CodS, xI and ESSprI improved in the intervention groups. UWS, SWS and SpF were higher in the intervention groups compared with the control group, but these differences were not significant except for SpF in the saline/tA group at t24 (p=0.005). Conclusions Irrigation of the major salivary glands in patients with SS enhances salivary flow and reduces xerostomia up to 6 months after sialendoscopy.