BACKGROUND: The association between progressive supranuclear palsy (PSP) and sleep disorders, particularly periodic limb movements in sleep (PLMS), remains inadequately studied, despite their impact on disease progression and quality of life. OBJECTIVES: This study aims to assess the prevalence and severity of sleep disorders in PSP, with a focus on PLMS, in comparison to Parkinson's disease (PD). METHODS: 11 patients with PSP and 10 patients with PD completed validated sleep questionnaires and underwent home-based polysomnography. RESULTS: Patients with PSP reported significantly poorer sleep quality and greater insomnia severity than those with PD, as evidenced by differences in the Pittsburgh sleep quality index (p=0.039) and insomnia severity index (p=0.001). Polysomnographic findings revealed more pronounced disruption of sleep architecture in PSP, including a reduction in N3 sleep stage (p=0.020), and decreased REM sleep (p=0.048). PLMS were more frequent among patients with PSP compared to those with PD, although this difference was not statistically significant. CONCLUSIONS: Sleep disturbances are more severe in PSP than in PD, including patients with PSP exhibiting higher rates of insomnia and greater disruption of sleep architecture. PLMS in PSP are at least as common as in PD and are linked to heightened sleep complaints. These exploratory findings underscore the necessity for further research to elucidate the distinct pathophysiological mechanisms of sleep dysfunction in tauopathies and synucleinopathies, and to guide the developement of targeted therapeutic interventions.