Resumo. ABSTRACT The circadian rhythm of motor performance is synchronized to the body temperature rhythm, with highest values occurring in the afternoon, and to the sleep-wake cycle, with individual preferences of sleep-onset and wake-up times. The aim of this study was to determine whether differences between the preferences of hours of sleep and wake (morningness-eveningness) have an impact on reaction times (RT) and motion (TM) measured in the early morning and late afternoon. Forty students, 20 morning-types and 20 evening-types, performed by the morning and by the afternoon a key-pressing task with measures of simple reaction time and movement time. According to the results, both morning-types and evening-types showed lower simple reaction times in the afternoon as compared to values in the morning and morning-types obtained lower movement times than evening-types, both in the morning and in the afternoon. Thus, it can be concluded that morningness-eveningness influenced the movement time, but not the simple reaction time.