To study the emergence of attention deficits in early childhood, the diagnostic team of an early education program documented the occurrence of poor concentration, distractibility, behavioral disorganization, poor self-monitoring, and overactivity in a group of 174 children followed prospectively from birth to school entry. Persistent attentional problems were identified in 5% of the children; 8% had problems which abated before kindergarten. Over the period from birth to kindergarten, 40% of the preschool youngsters were found to have some attentional indicator, but many of the findings were minor or transient. This study points to (1) the clustering of persistent attentional concerns with other developmental and environmental concerns, (2) the substantial long-term consequences of early attentional problems and (3) the feasibility of early detection of some children with attentional disorders.