Aim: To determine the incidence of hospitalisations and risk factors for vascular complications experienced during early adulthood in patients with childhood onset type 1 diabetes. Methods: A population-based childhood onset type 1 diabetes cohort was identified from a statewide register (1992-2012). Data linkage was used to identify a matched comparison cohort. Hospital admissions data were extracted to follow up both cohorts into early adulthood (1975-2012). Results: The type 1 diabetes cohort (n = 1316) had a mean age of diagnosis of 9.5. years, 49.5% were women and mean age at the end of follow-up was 26.3. years (range 18-38). Within the type 1 diabetes cohort 32 (2.4%) were hospitalised with a vascular complication during early adulthood. Poor glycaemic control during paediatric management was associated with a significant increase in risk for ophthalmic complication with 19.4% (n = 12/62) of those with a mean HbA1c >. 12% (108. mmol/mol) diagnosed compared to 0.72% (n = 5/696) of those with mean HbA1c <. 9% (75. mmol/mol), adjusted hazard ratio 8.4 (95% CI 2.0, 34.7). Conclusion: Severe vascular complications requiring hospital admission continue to be observed during early adulthood. Both women and those with poor glycaemic control are at increased risk of requiring a hospital admission for these complications during early adulthood.