Background: Psoriasis is a chronic autoimmune skin condition with long-term impairment and is considered as one of the five diseases that the World Health Organization (WHO) identified as having an enormous burden on patients' sleep quality and impacts on daytime functioning and health status (Tas, et al., 2020). Aim of the study: Was to evaluate the effectiveness of sleep hygiene measures on quality of sleep, activities of daily living and disease severity among patients with psoriasis. Research design: A quasi-experimental design was utilized to conduct the current study. Setting: The study was conducted at Dermatology, Venereology and Andrology Unit, Specialized Medical Building, Main Mansoura University hospital, Egypt. Method: A purposive sample of 60 adult patients were randomly classified into two equal groups 30 patients for each group. Tools of data collection: Four tools were used for data collection: Patients' Interviewing Questionnaire, Sleep Quality Scale (SQS), Psoriasis Area Severity Index (SPASI) and Katz Index of Independence in Activities of Daily Living. Results: Revealed a statistically significant relationship (p 0.05) between the Katz Index of Independence with the study group's scores on the sleep quality scale and the patients' psoriasis area severity index. Furthermore, there was an inverse correlation between sleep quality scale and Katz Index of Independence with psoriasis area severity index (- 0.437) and a positive correlation between sleep quality (0.453) and Katz Index of Independence. (- 0.398). Conclusion: The sleep hygiene measures had a positive effect on enhancing the level of sleep quality with reducing the severity of the disease and improving the performance of daily living activities among the study group's patients. Recommendation: The sleep hygiene measures should be involved in the routine nursing management plane for patients with psoriasis.