Introduction Cerebral palsy (CP) is the most common physical disability of childhood worldwide. Historically the diagnosis was made between 12 and 24 months, meaning data about effective early interventions to improve motor outcomes are scant. In high-income countries, two in three children will walk. This evaluator-blinded randomised controlled trial will investigate the efficacy of an early and sustained Goals–Activity–Motor Enrichment approach to improve motor and cognitive skills in infants with suspected or confirmed CP.Methods and analysis Participants will be recruited from neonatal intensive care units and the community in Australia across four states. To be eligible for inclusion infants will be aged 3–6.5 months corrected for prematurity and have a diagnosis of CP or ‘high risk of CP’ according to the International Clinical Practice Guideline criteria. Eligible participants whose caregivers consent will be randomly allocated to receive usual care or weekly sessions at home from a GAME-trained study physiotherapist or occupational therapist, paired with a daily home programme, until age 2. The study requires 150 participants per group to detect a 0.5 SD difference in motor skills at 2 years of age, measured by the Peabody Developmental Motor Scales-2. Secondary outcomes include gross motor function, cognition, functional independence, social–emotional development and quality of life. A within-trial economic evaluation is also planned.Ethics and dissemination Ethical approval was obtained from the Sydney Children’s Hospital Network Human Ethics Committee in April 2017 (ref number HREC/17/SCHN/37). Outcomes will be disseminated through peer-reviewed journal publications, presentations at international conferences and consumer websites.Trial registration number ACTRN12617000006347.
