ABSTRACT Purpose To compare performance between children with typical speech acquisition, phonological disorders, and childhood apraxia of speech for the variables overall articulatory accuracy and consistency of the Dynamic Evaluation of Motor Speech Skill - Brazilian Portuguese version (DEMSS-BR). Methods Study participants were 18 children of both genders aged 4 years and 6 months to 5 years and 8 months. The sample was divided into three groups: six children with typical speech acquisition (TSA), six children with phonological disorder (PD), and six individuals with childhood apraxia of speech (CAS). All participants were submitted to the DEMSS-BR and had their subscores of speech accuracy and consistency measured. Performance comparison between the groups was statistically evaluated using the Mann-Whitney U Test. Results Participants in the group with CAS presented poorer performance for the variables overall articulatory accuracy and consistency compared with those of participants in the other two groups. Conclusion The group of children with childhood apraxia of speech presented poorer performance on the DEMSS-BR compared with those of the groups with typical speech acquisition and phonological disorders. The study demonstrated that the DEMSS-BR assists with differential diagnosis of children with speech sound disorders.