Background: Due to significant medical improvements, persons with Down syndrome now live well into adulthood. Consequently, primary care for adults with Down syndrome needs to incorporate routine care with screening for condition-specific comorbidities. This study seeks to evaluate the adherence of primary care physicians to age- and condition-specific preventive care in a cohort of adults with Down syndrome. Methods: In this retrospective observational cohort study, preventive screening was evaluated in patients with Down syndrome aged 18-45 years who received primary care in an academic medical centre from 2000 to 2008. Comparisons were made based on the field of patients' primary care providers (Family or Internal Medicine). Results: This cohort included 62 patients, median index age = 33 years. Forty per cent of patients received primary care by Family Physicians, with 60% seen by Internal Medicine practices. Patient demographics, comorbidities and overall screening patterns were similar between provider groups. Despite near universal screening for obesity and hypothyroidism, adherence to preventive care recommendations was otherwise inconsistent. Screening was "moderate" (50-80%) for cardiac anomalies, reproductive health, dentition, and the combined measure of behaviour, psychological, or memory abnormalities. Less than 50% of patients were evaluated for obstructive sleep apnea, atlanto-axial instability, hearing loss or vision loss. Conclusions: We observed inconsistent preventive care in adults with Down syndrome over this 8.5-year study. This is concerning, given that the adverse effects of many of these conditions can be ameliorated if discovered in a timely fashion. Further studies must evaluate the implications of screening practices and more timely identification of comorbidities on clinical outcomes. (Contains 3 figures and 5 tables.)