On the basis of teachers' ratings of impulsivity, a group of 20 preschool children with a mean age of 51 months were assigned to groups of impulsive and non-impulsive subjects. Both groups were administered two measures of impulsivity as pre- and posttests: the Draw-a-Line Test and an adapted version of the Matching Familiar Figures Test. In addition, children were videotaped in pre- and posttest sessions while independently completing a selective attention task. Impulsive children participated in 15 training sessions, each of 15 minutes duration, that were designed to promote the effective use of spontaneous private speech during goal-directed activity. The effective use of private speech was facilitated through sensitive increases of task difficulty and contingent withdrawal of trainer control. Children's private speech and degree of impulsivity were assessed. Findings indicated that impulsive children emitted higher amounts of private speech before training, especially self-verbalizations typically considered "immature," such as descriptions of self and environment. Training reduced the amount of both low-level and total private speech emitted by the impulsive preschoolers. No effects of training were found on the laboratory measures of impulsivity. (Author/RH)