Background: Despite a shift in diabetes care internationally from secondary to primary care, diabetes care in the Republic of Ireland remains very hospital-based. Significant variation in the facilities and resources available to hospitals providing outpatient diabetes care have been reported in the UK. The aim of this study was to ascertain the structure of outpatient diabetes care in public hospitals in the Republic of Ireland and whether differences existed in services provided across hospitals.Methods: We conducted a cross sectional observational study of the 36 public general hospitals providing adult outpatient diabetes care in the Republic of Ireland. Data relating to numbers of specialist medical, nursing and allied health professionals, waiting times for new and return patients, patterns of discharge back to primary care and engagement in quality improvement initiatives were recorded.Results: Thirty-five of the 36 eligible hospitals participated in the study. Sixty percent of these had at least one consultant endocrinologist in post, otherwise care delivery was led by a general physician. Waiting times for newly diagnosed patients exceeded six months in 30% of hospitals and this was higher where an endocrinologist was in place (47% V 7%, p = 0.013). Endocrinologists were more likely to have developed subspecialty clinics, access to allied health professionals and engage more in quality improvement initiatives but less likely to discharge patients back to primary care than general physicians (76 v 29%, p = 0.005).Conclusions: Variations exist in the structure and provision of diabetes care in Irish hospitals. Endocrinology-led services have more developed subspecialty structures and access to specialist allied health professionals and engage more in quality improvement initiatives. Nonetheless, waiting times are longer and discharge rates to primary care are lower than for non-specialty led services. Further studies to determine the extent to which case-mix variation accounts for these observations are warranted. Aspects of hospital-based outpatient care could be developed further to ensure equitable services are provided nationally. At a time when the delivery of diabetes services in primary care is being promoted, further research is warranted on the factors influencing the successful transition to primary care.