Background: The conversational speech of most children can be understood by people outside the family by the time they reach 4 years. However, for some children, speech sound disorders (SSDs) persist into their early school years, and beyond, despite adequate hearing, oromotor function, and language learning opportunities. One explanation for children's SSDs are domain-general cognitive-linguistic deficits that impair the child's ability to correctly derive rules governing how speech sounds legally combine to form words in a specific language. Aims: To explore whether there are differences in performance on executive function tasks between children who make speech errors characteristic of phonological delay and those who make speech errors characteristic of phonological disorder. Methods & Procedures: Twenty-six children aged from 3;6 to 5;2 (13 with phonological delay and 13 with phonological disorder), matched pairwise for age and sex (nine males), were assessed on tasks measuring cognitive flexibility (rule abstraction and cognitive shift) and phonological working memory. Outcome & Results: For the cognitive flexibility tasks, the performance of children with phonological delay was significantly better than that for children with phonological disorder, but there were no group differences for the phonological working memory task. Conclusions & Implications: Children with phonological disorders might benefit from intervention programmes that incorporate training in cognitive flexibility.