Psoriasis alters patients' quality of life. Among the disorders associated with psoriasis, sleep disorders are common, although they are not directly assessed by most quality-of-life scores. Thus, the specific evaluation of sleep disorders using dedicated scores is necessary, especially because such disorders alter patients;' physical and psychological health. The relationship between psoriasis and sleep disorders has been shown in numerous studies, but has not yet been fully elucidated. The aim of this study was to update knowledge of sleep disorders in patients with psoriasis, through a review of the scientific literature since 1980. This work covers several topics of interest, such as sleep assessment methods, the prevalence of sleep disorders in patients with psoriasis, factors predictive of sleep disorders in patients with psoriasis, the impact of sleep disorders on comorbidities and quality of life, pathogenic mechanisms, obstructive sleep apnoea and restless leg syndromes, and the impact of biotherapy treatments on sleep disorders in patients with psoriasis.