BACKGROUND:
The increasing exposure of young children to electronic devices represents an emerging public health challenge, particularly in low- and middle-income countries, where access to digital technologies has expanded rapidly, often without adequate educational strategies. Excessive screen use, especially during nighttime, may impair sleep quality, which is essential for healthy child development.

OBJECTIVE:
To evaluate the association between daily screen time and sleep quality in children in early childhood, considering public health implications in middle-income countries.

METHODS:
A cross-sectional study was conducted with caregivers of children aged 6 months to 6 years enrolled in early childhood education at a school in Vitória, Espírito Santo, Brazil. Data were collected using a structured questionnaire addressing screen use habits and sleep patterns. Sleep quality was assessed using the Children’s Sleep Habits Questionnaire (CSHQ). Statistical analyses examined associations between screen time and sleep disturbances, with stratification by age group.

RESULTS:
Data from 212 children were analyzed. The most frequent daily screen time was one hour. Sleep disturbances were identified in 77.4% of the sample. Screen exposure exceeding one hour per day was significantly associated with a higher prevalence of sleep disturbances (p < 0.002), particularly among children younger than two years (p < 0.027). A significant correlation was observed between screen time and the global sleep disturbance score (r = 0.194; p < 0.005), with a stronger correlation in children under two years of age (r = 0.321; p < 0.007). Significant associations were also found with parasomnias and daytime sleepiness (p < 0.001).

CONCLUSIONS:
Greater screen exposure was associated with poorer sleep quality in early childhood, highlighting the need for educational strategies and health promotion actions aimed at responsible screen use in contexts of rapid digital transformation.