Purpose: REM behaviour sleep disorder (RBD) is a parasomnia and involves sudden movements and/or vocalizations that reflect the dream content. This disorder is a common symptom of neurodegenerative diseases or their prodromal symptom. Until recently, clonazepam was the most commonly used drug to relieve symptoms of RBD. The aim of the article is to describe successful RBD treatment with melatonin.

Case description: A case of a 56-year-old man with a history of symptoms characteristic for RBD was presented. The initial diagnosis was confirmed by video-polysomnography in the course of which clinical episodes and periods of muscle atonia during REM sleep were recorded. The cause of RBD was not identified, an idiopathic form of the disorder was diagnosed. Melatonin was used for treatment in the target dose of 5 mg/day with a satisfactory result. Due to an increased risk of a neurodegenerative disease, the patient remained under care of a neurologist.

Comment: Due to more frequently reported effectiveness of melatonin in RBD treatment with a low risk of adverse reactions and interactions with other drugs, it is worth considering its use before the decision to administer clonazepam, especially in the elderly.