BackgroundOsgood–Schlatter disease (OSD) is a non-traumatic knee problem that is primarily observed in sports-active children and adolescents aged 8–15 years.AimTo determine the incidence of OSD and to gain an insight into the management of children and adolescents with OSD in general practice.Design and settingA retrospective cohort study was conducted using a healthcare database containing full electronic health records of over 200 000 patients in general practice in and around the Dutch city of Rotterdam.MethodPatients with a new diagnosis of OSD from 1 January 2012 to 31 December 2017 were extracted using a search algorithm based on International Classification of Primary Health Care coding and search terms in free text. Data on the management of OSD were manually interpreted.ResultsThe mean incidence over the study period was 3.8 (95% confidence interval [CI] = 3.5 to 4.2) per 1000 person–years in those aged 8–18 years. Boys had a higher incidence rate of 4.9 (95% CI = 4.3 to 5.5) compared with girls (2.7, 95% CI = 2.3 to 3.2). Peak incidence was at 12 years of age for boys and 11 years for girls. Advice was the most commonly applied strategy (55.1%), followed by rest (21.0%), referral for imaging (19.5%), and physiotherapy (13.4%).ConclusionTo the authors’ knowledge, for the first time the incidence of OSD has been calculated using GP electronic medical files. There is a discrepancy, especially for imaging and referral to a medical specialist, between the current Dutch general practice guidelines and how GPs actually manage the condition in clinical practice.