Introduction Glucocorticoid-induced osteoporosis (GIOP) is associated with elevated fracture risk. Practice guidelines have been published to reduce this risk but are insufficiently followed in everyday practice. The objectives of this study were to estimate fracture incidence in patients exposed to oral glucocorticoids and to analyse the impact of glucocorticoid use on fracture incidence. Materials and methods This retrospective cohort study was performed using the Medical Data Vision (MDV) claims database from Japan. All patients aged ≥ 18 years initiating oral glucocorticoids and fulfilling Japanese guideline criteria for starting prophylactic osteoporosis treatment between 2009 and 2019 were identified. These were matched to a cohort of unexposed controls using propensity score matching. Fracture incidence in the two cohorts were compared using a Fine-Gray proportional sub-distribution hazard model. Results 13,090 glucocorticoid-exposed cases were compared to 13,090 unexposed controls. The 1-year fracture rate (all sites) was 9.3 95% CI 8.8–9.8 in cases and 5.8 5.4–6.2 in controls. One-year vertebral fracture rates were 4.3 4.0–4.7 and 2.3 2.1–2.6 respectively. In the multivariate analysis, the use of glucocorticoids was associated with an increase in the incidence of osteoporotic fractures (hazard ratio: 1.63 1.51–1.76). The glucocorticoid-associated risk tended to be higher in subgroups of patients with rheumatoid arthritis, asthma, COPD and in those aged < 65 years. Conclusion Oral glucocorticoid use is associated with an increase in fracture incidence. It is necessary to raise awareness of GIOP and to take public health measures to change the perceptions and behaviour of doctors prescribing glucocorticoids.