Despite the importance of parental scaffolding for later child cognitive outcomes and academic achievement, sources of individual variation in scaffolding are not fully understood. Scaffolding places extensive demands on cognitive capacity, including planning, flexibly shifting, and inhibition. Executive function (EF) is therefore a parental cognitive ability especially important for effective scaffolding. In this study, parents and preschool-aged children completed a challenging puzzle to assess scaffolding. EF and verbal ability were measured for parents and children. Parental verbal ability was used as an index of global higher-order cognitive function. Higher levels of parental EF related to more effective scaffolding, above and beyond parental verbal ability and independent of child cognitive level. These results highlight the significance of considering parental cognitive capacities in future studies to better understand the sources of individual differences in scaffolding.