This longitudinal study examined individual differences and correlates of focused attention when toddlers were approximately 18 months old (T1; n = 256) and a year later (T2; n = 230). Toddlers' attention and negative emotionality were reported by mothers and non-parental caregivers and rated globally by observers. Toddlers' focused attention also was observed during two mother-child interactions and an independent play task. Measures of maternal emotional support and control were obtained via self-report and observation. Some contemporaneous relations among indices of toddlers' attention were obtained, particularly for observed measures. Moreover, all measures of attention demonstrated stability across time. Negative emotionality was negatively related to toddlers' observed attention at both ages, whereas maternal praise had positive concurrent associations. Maternal control was negatively related to observed attention at T2 and also predicted longitudinally, but only for children who initially had low or moderate attention. The findings suggest that individual differences in focused attention evidence stability early in life but can be influenced by adult socialization. (Contains 5 tables.)