Introduction The prevalence of oropharyngeal dysphagia (OPD) in children with cerebral palsy (CP) is estimated to be between 19% and 99%. OPD can impact on children's growth, nutrition and overall health. Despite the growing recognition of the extent and significance of health issues relating to OPD in children with CP, lack of knowledge of its profile in this subpopulation remains. This study aims to investigate the relationship between OPD, attainment of gross motor skills, growth and nutritional status in young children with CP at and between two crucial age points, 18–24 and 36 months, corrected age.

Methods and analysis This prospective longitudinal population-based study aims to recruit a total of 200 children with CP born in Queensland, Australia between 1 September 2006 and 31 December 2009 (60 per birth-year). Outcomes include clinically assessed OPD (Schedule for Oral Motor Assessment, Dysphagia Disorders Survey, Pre-Speech Assessment Scale, signs suggestive of pharyngeal phase impairment, Thomas-Stonell and Greenberg Saliva Severity Scale), parent-reported OPD on a feeding questionnaire, gross motor skills (Gross Motor Function Measure, Gross Motor Function Classification System and motor type), growth and nutritional status (linear growth and body composition) and dietary intake (3 day food record). The strength of relationship between outcome and exposure variables will be analysed using regression modelling with ORs and relative risk ratios.

Ethics and dissemination This protocol describes a study that provides the first large population-based study of OPD in a representative sample of preschool children with CP, using direct clinical assessment. Ethics has been obtained through the University of Queensland Medical Research Ethics Committee, the Children's Health Services District Ethics Committee, and at other regional and organisational ethics committees. Results are planned to be disseminated in six papers submitted to peer reviewed journals, and presentations at relevant international conferences.