This study investigated retrospectively the long‐term efficacy and safety of radiotherapy (RT) to the major salivary glands as treatment of sialorrhea in patients with parkinsonism. Twenty‐eight patients received a bilateral dose of 12 Gy to the parotid and part of the submandibular glands between 2001 and 2006. Severity of sialorrhea and adverse events were assessed at 1 and 6 months post‐RT and finally in the first quarter of 2007. Item 6 of the activities of daily living‐section of the Unified Parkinson's Disease Rating Scale was used as primary endpoint. Quality of life (QoL) pre‐ and post‐RT was investigated using a shortened Parkinson's Disease Questionnaire‐8. Sialorrhea had improved significantly at 1 month post‐RT and this effect was maintained for at least 1 year. Most frequent adverse events were loss of taste and a dry mouth; however, 75% of these adverse events were transient. QoL had improved significantly on the long term. The clinical global impression scores at the final follow‐up showed that 80% of patients were satisfied. It was concluded that RT is an effective and safe treatment of sialorrhea on the long term in patients with parkinsonism. © 2007 Movement Disorder Society