BACKGROUND:In children with Down Syndrome (DS), as in other groups of special needs children, development depends crucially on the degree to which parents provide appropriate stimulation and effective support. The majority of recent studies investigating interactions between parents and children with DS have been conducted on mothers. METHOD:Through observation of child solitary play, child collaborative play with their father, and father play with their child, the current study focused on paternal contributions to child play in association with the effective quality of father-child interactions. A total of 19 children (M chronological age = 35.32 months, SD = 10.35; M mental age = 19.58, SD = 5.43) with DS and their fathers participated in the study. Two 10-min sessions, of child solitary play and collaborative play with their father, were videorecorded. A coding system for exploratory and symbolic play was applied to both sessions, and the Emotional Availability (EA) Scales were independently applied to the collaborative play session as a measure of the effective quality of the father-child interaction. RESULTS:Children showed more symbolic play during collaborative sessions compared with solitary sessions. Bivariate correlations showed positive associations between father play and child exploratory and symbolic play. Cluster analysis identified dyads in low, medium and high EA groups, which differed in terms of each partner's play. Specifically, both fathers and children of high EA dyads were more likely to show more symbolic play and less exploratory play than those with low EA dyads. CONCLUSIONS:Our findings enrich the theoretical perspective that dyadic interactions based on emotional involvement may lead to enhanced cognitive functioning in children with DS.