The effectiveness of using parents as interventionists for their children and other parents was examined. A multiple baseline design was employed to measure the effects of specific intervention techniques on teaching skills of three parents of toddler-aged children with Down syndrome. The first parent was trained by a professional interventionist on the use of the techniques. This parent then trained a second parent, who then trained a third parent. A fidelity-of-implementation measure indicated that the parents implemented the training procedures appropriately when training another parent. The effectiveness of the intervention techniques was measured through an observational code that assessed parent and child behavior during teaching sessions. Results suggest that training had a functional effect on the parents' use of the selected intervention techniques. The intervention also had a functional effect on the children's percentage of correct responding during the teaching session.