Objective To examine the Manukau Salivary Symptom Score (MSSS) questionnaire as a validated tool to assess obstructive sialadenitis-specific symptoms to both indicate disease severity and assess the outcome after sialendoscopic procedures. Study Design A prospective observational study was performed from 2010 to 2019 comprising 164 patients undergoing sialendoscopy for nonneoplastic chronic obstructive salivary gland disease (COSGD). Setting Department of Otolaryngology–Head and Neck Surgery at the Manukau Surgical Centre, Auckland, New Zealand, between June 2010 and September 2019. Methods A prospective observational study was performed from 2010 to 2019 comprising 164 patients undergoing sialendoscopy for nonneoplastic COSGD. Patients completed the MSSS preoperatively and at postoperative follow-up. Statistical tests were used to compare pre- and postoperative answers. Cronbach’s α was used to measure internal consistency. Finally, construct validity was determined by comparing the 5-question MSSS questionnaire to the preexisting 20-question Chronic Obstructive Sialadenitis Symptoms (COSS) questionnaire. Results Postoperatively, patients had significant improvements in pain, eating, talking, swelling, and quality of life ( P < .001). The MSSS questionnaire was found to have high internal consistency (α = 0.938). Questions in the MSSS had a very strong positive correlation with 3 COSS questions, a strong positive correlation with 8, a moderate positive correlation with 4, and a weak positive correlation with 1. Four COSS questions were not considered relevant and were not included in the MSSS questionnaire. Conclusion The MSSS questionnaire is a simple, validated questionnaire that is useful for assessing the impact of sialendoscopy in patients with COSGD.