The sleep and wake cycle is influenced by endogenous and socio-environmental factors, which change throughout ontogenesis and in the face of individuals' relationships with time and society. These changes are expressed in the form of specific sleep patterns for the age groups, which often conflict with the needs of everyday life imposed by the society and environment in which we live. In childhood, children tend to be in the morning and show a gradual reduction in sleep duration as the nervous system matures, although they maintain a high need for sleep in relation to other age groups. The transition to adolescence is marked by a phase delay, characterized by late sleeping and waking times, expressing a tendency to evening and the need for sleep between 8 and 10 am. When faced with the start time of the school, in the morning shift, they may present changes in the natural biological rhythm due to these social factors, leading to sleep deprivation, daytime sleepiness and negative impacts on cognitive processes, such as attention. Thus, the present study aims to compare sleep patterns, morning drowsiness and the attentional process between children in early childhood education and high school adolescents in the morning school shift. The sample consisted of 205 students from the morning shift, among them, 66 children from 4 to 6 years old from early childhood education and 139 adolescents, between 15 and 17 years of high school from private schools located in the city of Natal / RN. The data are part of a bank of the Laboratory of Chronobiology and Behavior. The following instruments were used: 1) Sleep habits questionnaire (children: general sleep habits and adolescents questionnaire: “Health and Sleep”), 2) sleep diary (for 9 days), 3) sleepiness scale of Maldonado and the 4) task of continuous execution to evaluate the attention. Sampling was cross-sectional, however not all individuals surveyed participated in all stages of collection. The variables related to sleep patterns, drowsiness and attention will be compared between age groups using ANOVA. The characterization of the sleep and wake cycle, daytime sleepiness and attention in children in early childhood education and high school adolescents will contribute to analyze the influence of the morning school schedule on the biological rhythm of these individuals.