Abstract Introduction: Racial and socioeconomic disparities are known to negatively affect sleep duration in school-aged children and adults. Little is known about how very young African American (AA) and Caucasian (C) children (1-year-olds) differ in nocturnal and daytime sleep duration and how this may affect daytime behavioral patterns. The purpose of this study was to determine differences in total sleep duration between AA and C 1-year-olds and how nighttime and daytime total sleep hours and number of minutes awake during the night relates to objective behavioral performance measures. Methods: We analyzed data from the first-year clinic visits (N=1056) (mean SD) (1.08 years 0.12) of predominantly AA (n=663) and C (n=393) children living in Shelby County, TN enrolled in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study. T-tests for differences between total nocturnal and daytime sleep hours and number of minutes awake during the night (all reported by parent) between races and bivariate correlations determined if sleep periods were associated with Brief Infant Toddler Social Emotional Assessment (BITSEA) total and subscale scores for externalizing and internalizing behavior problems. Results: AA children slept significantly fewer hours than C children during daytime (7am-7pm) (2.6 1.5 v 2.9 1.1, p<0.001) and nighttime (7pm - 7am) hours (9.2 1.4 v 10.4 1.1) respectively. AA were awake more minutes during the night (18.7 40.9) than C (8.9 25.3, p <0.001). Total nighttime sleep hours were significantly correlated with Externalizing (r= -.20, p < 0.001) and Internalizing BITSEA subscales (r= -.20, p < 0.001) as were nighttime wake minutes (r= .14, p<0.001 and r= .11, p<0.001, respectively). Daytime hours of sleep were non-significantly correlated to the BITSEA scores. Conclusion: Urban 1-year-old AA children sleep significantly less during nighttime and daytime hours than their C counterparts. Fewer total night minutes of sleep corresponded with higher (i.e, more impaired) scores for externalizing and internalizing behaviors while more minutes of wake during the night resulted in similar behavior patterns. More focus must be given to alerting urban communities of the importance of adequate nighttime sleep for their very young children. Support (If Any): Urban Child Institute