The purpose of this project was to investigate the maintenance of focused attention in the first 5 years. In Study 1, 67 children were seen at 1, 2, and 3.S years of age in free play with a number of age-appropriate toys. The duration of focused attention increased significantly over the ages studied. At 1 year, the children's focused attention showed a decline within the session; at the 2 older ages, however, focused attention neither decreased nor increased. In Study 2, children at 2.5,3.5, and 4.5 years were also seen in free play. The results replicated the significant increase in focused attention over age and the lack of change within the session. Older children focused attention significantly more on construction and problem solving than did younger children, and manifested less inattention by physical movement away from the toys. The observed development in focused attention, therefore, is probably related both to the increased variety and complexity of the child's activities and to increasing inhibitory control.