Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by pruritus, xerosis and eczema, causing sleep disorders. This study purpose was to examine sleep disorders among children with AD, correlating with disease severity scores, lifestyle, and sleep quality, before and during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This is a longitudinal, analytical, prospective, uncontrolled study included 26 patients with AD aged 5–10 years from the Pediatric Dermatology Clinic at a tertiary-care hospital. The Sleep Disturbance Scale for Children Questionnaire and questions about sleep hygiene and lifestyle habits were were used. The severity of AD was determined by the Patient-Oriented Eczema Measure (POEM) index. The first evaluation was presential conducted from October 2019 to March 2020 and the second from September to December 2020 by telephone interviews. Results: The severity of AD was considered mild in 76.92% patients in both the evaluations. Sleep disorder was present in 17 (65.38%) patients in the first evaluation and in 11 (42.30%) in the second ( p=0.04). In the first evaluation, disorders of initiating and maintaining sleep (DIMS) was more frequent in moderate-to-severe AD than in mild AD (83.33% vs. 11.11%, p=0. 0025). During the pandemic, six patients (23.07%) reported improvement in sleep quality. Conclusion: Sleep quality was negatively influenced by the severity of AD. During the COVID-19 pandemic, there were changes in lifestyle habits and improvement in sleep quality, despite the absence of changes in disease severity.