A multiple-baseline-across subjects design was used to evaluate the utility of a self-instruction programme with five preschool children with Down Syndrome. Parents taught object counting to their children using first an intervention implemented as a comparison (the Macquarie programme), and then following a self-instruction package. A probe was taken for generalisation. The results found no clear support for the use of self-instruction training in teaching children with Down Syndrome how to count. Some support for interventions providing metacognitive strategies was found after a more in­ depth look at the type of error made by these children. Several similarities were found between counting ability of the children in the current study and previous research in this area. Success in the transfer of training setting was mixed following both interventions.