Background Transition from pediatric to adult healthcare for adolescents with chronic health conditions has emerged as a critical period influencing health outcomes. Suitable transition readiness measures are necessary to facilitate effective planning. Currently, there is little consensus about well-validated transition readiness measures. The purpose of this systematic review was to identify best practices in transition readiness measurement for adolescents and young adults with chronic health conditions. Data sources Academic databases searched included PubMed, Cumulative Index to Nursing and Allied Health Literature, Google Scholar and Athabasca University Library’s Discover. Study selection Articles were included that discussed the development and psychometric properties of transition readiness measures for adolescents and young adults (11–25 years) with chronic health conditions and/or that utilized a previously developed measure. Data extraction The primary and secondary reviewers extracted data from the selected articles as per the data extraction tool developed for this review. Results Forty-eight articles, representing 19 tools, were included in the review. Ten of the tools were disease-specific; nine were disease-neutral. According to the Cohen criteria, eight measures were “well-established assessments”. The Transition Readiness Assessment Questionnaire was deemed the best measure of transition readiness available. The literature search included only articles published in peer-reviewed journals; measures nearing completion or awaiting publication were not included. In addition, only English manuscripts were included, many from North America. Conclusions Despite national practice guidelines and ongoing policy development, there is slow movement towards achieving a gold standard or best-practice measure of transition readiness.