There is continuing debate about the origins of productive morphological errors in children with speech sound disorders. This is the case for children with theorised phonetic and motor disorders, such as children with childhood apraxia of speech (CAS, e.g., Ekelman & Aram, 1983; McNeill & Gillon, 2013). The morphological skills of children with CAS remain relatively unexplored in pre-schoolers. We investigated English morphology in a retrospective, cross-sectional design of 26 children aged 4–5 years who completed the Clinical Evaluation of Language Fundamentals—Preschool (2nd edition; Wiig, Secord & Semel, 2006). The research aims were to determine: (1) the language profile of the children, (2) the accuracy of each morpheme type produced, and (3) how many of those morphological errors are explained by speech errors (clusters, late developing phonemes, central vowels or weak syllable stress)? The results indicate the group of children with CAS had poorer expressive language skills than receptive skills and 48% demonstrated difficulties with morphology in word structure and recalling sentences subtests. The children had poor accuracy and inconsistent production of a range of morphemes and despite many errors due to the speech characteristics of the stimuli on the CELF-P2, motor speech concerns could not explain all the child’s morphological errors. The results suggest morphological difficulties are co-morbid to CAS and when this occurs, treatment for morphosyntax is indicated. There are also significant clinical implications in the assessment of morphosyntax for children with CAS which are discussed.