Abstract Introduction: Parkinson’s disease (PD) is mainly characterized by motor symptoms including muscle rigidity, resting tremor and bradykinesia. However, the management of the non-motor symptoms represent a relevant clinical challenger in PD. These non-motor symptoms include cognitive and sleep disturbance and there is evidence that cannabinoids may represent alternative and effective treatments for non-motor symptoms of PD. Methods: Therefore, this study addressed the effects of oral treatment with cannabis extract on cognition, insomnia, and daytime sleepiness in six patients with moderate PD. The patients were randomized to receive two different doses of a cannabis extract: THC:CBD 250:28 μg/day (n = 3) or 1000:112 μg/day (n = 3). The assessment of...