The predictive relation between neonatal behavior and temperament at 24 months was examined for 67 infants. Behaviors rated by trained examiners at both ages were aggregated into composite scores to provide a more reliable indicator of individual differences than single-item scores. Longitudinal analyses revealed several significant relations between the two ages, most notably that irritable neonates were rated as more upset, less attentive to stimuli, and less responsive to the staff at 24 months. The common variable describing behavior at both ages was related to emotionality. Examination of extreme groups on ratings of emotional tone indicated that the distressed toddler had high irritability ratings as a neonate, but the more pleasant toddler was not different from the average group in neonatal irritability scores. It was concluded that a modest predictive relation between temperament variables was demonstrated from the neonatal period to 24 months.(PsycINFO Database Record (c) 2016 APA, all rights reserved)