Imitation of tongue protrusion and mouth opening was studied in eight infants with Down's syndrome. Five of the children were observed at approximately 1 mo, seven around 3 mo, and seven at 4 mo. The only significant group result revealed imitation of tongue protrusion at 1 mo. In addition, a descriptive analysis of each child's response pattern during the presentation period showed that all five children observed at 1 mo imitated tongue protrusion and that four of them also seemed to imitate mouth opening. The result for the 3-mo observation was somewhat inconsistent. All but one of the infants increased their response rates of both tongue protrusion and mouth opening when mouth opening was modeled. At 4 mo imitation seems to disappear. Overall, the findings are in agreement with what is known from typically developing children.