Melatonin has been shown to improve sleep quality in Parkinson's disease (PD) patients with good safety and tolerability. Beyond its neurological benefits, emerging evidence suggests that melatonin may exert cardioprotective effects, which could be relevant in the context of sudden unexpected death in PD (SUDPAR). PD is associated with high mortality rates, and autonomic dysfunction and cardiac abnormalities may play a role in SUDPAR. Translational studies suggest that melatonin concentrations could serve as potential biomarkers for cardiac dysfunction in PD. Melatonin supplementation has demonstrated neuroprotective properties by modulating apoptosis, autophagy, oxidative stress, inflammation, α-synuclein aggregation, and dopamine loss. Additionally, clinical data indicate that melatonin levels are altered in patients with coronary heart disease, heart failure, and stroke. Reduced melatonin production is associated with increased risk of cardiac events and sudden cardiac death. Given its anti-inflammatory, antioxidant, immunomodulatory, and vasomotor properties, melatonin may represent a promising adjunctive therapy for PD, potentially mitigating both neurological and cardiovascular risks.