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Objectives The primary aim of the SCRUTINY study was to determine the population prevalence of shoulder imaging abnormalities in asymptomatic adults. Secondary aims were to synthesise prevalence data reported in studies including other study populations as well as to compare the prevalence of imaging abnormalities in adults with and without symptoms.Method We systematically reviewed studies reporting prevalence of X-ray, ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) abnormalities in adults without shoulder symptoms (PROSPERO registration number CRD42018090041). This report presents the glenohumeral joint imaging findings. We searched Ovid MEDLINE, Embase, CINAHL and Web of Science from inception to June 2023 and assessed risk of bias using a tool designed for prevalence studies. The primary analysis was planned for the general population. The certainty of evidence was assessed using a modified Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) for prognostic studies.Results This is the first systematic review summarizing the existing evidence on the prevalence of glenohumeral joint abnormalities in asymptomatic shoulders. We identified only two population-based studies for the outcomes of interest as well as 33 studies with various study populations. There was a high variation in prevalence rates, age groups, genders, and outcome definitions between studies, but structural changes were common findings in asymptomatic shoulders both in population-based and other study populations. Overall, all studies were judged to be high risk of bias and the certainty of evidence was low or very low. Population prevalence of glenohumeral osteoarthritis ranged from 15% to 75% (2 studies, 846 shoulders). Prevalence of labral abnormalities, humeral head cysts and long head of biceps tendon abnormalities were 20%, 5%, 30% respectively (1 study, 20 shoulders). The prevalence of glenohumeral joint abnormalities were almost as common in asymptomatic as in symptomatic shoulders from the same study populations.Conclusions The population-based prevalence of glenohumeral joint imaging abnormalities in asymptomatic individuals remains uncertain, but may range between 30 and 75%. Better estimates are needed to inform best evidence-based management of people with shoulder pain.