Purpose: Although speech-language pathologists use parent-delivered home-practice, little is known about the quality of this practice and its relation to treatment efficacy. This study reports both treatment outcomes and fidelity following combined clinician-parent delivery of Rapid Syllable Transition (ReST) treatment. Method: Five children aged 5:1-11:7 with childhood apraxia of speech received 12 treatment sessions; six clinic-based and six at home, using multiple baselines across participants design. We investigated the children?s acquisition of treated pseudo words, generalisation to untreated pseudo and real words, and maintenance of gains. We also assessed parent and clinician treatment fidelity and reliability of perceptual judgements. Result: Two children improved on all treated behaviours; two showed treatment effect on one of their two treated behaviours, and one child had no treatment effect. Only two children generalised to the majority of untreated items. Variable treatment fidelity was found across parents and aspects of treatment. Child outcome was likely influenced by multiple factors, including treatment fidelity, reliability of perceptual judgements and child factors. Conclusion: Combined clinician-parent delivery of ReST was less efficacious than previously reported clinician-only delivered ReST. Further investigation of the factors affecting outcome is recommended prior to clinical application of the combined model of service delivery.