OBJECTIVES: Despite the growing incidence of diabetes, the occurrence of complications requiring hospitalization has stabilized in the last decade. Advances in health care and improved access to innovative drugs may have led to these health gains. We aimed to explore the relationship between patients' access to newer oral anti-diabetic drugs (OADs) and the number and costs of hospitalizations attributable to diabetes. METHODS: For the period 2000-2009, we collected data on: 1) the number of hospital admissions and their costs attributable to diabetes; 2) the number of patients treated for diabetes per year and health region, based on the OADs consumption ("treated prevalence"); and 3) the evolution of the average "vintage" (year of marketing approval) of OADs. Using observations for 10 years and five regions, it was possible to estimate a multiple regression model explaining separately hospitalizations and hospital costs attributable to diabetes by regional fixed effects, "treated prevalence" and the average "vintage" of OADs.  RESULTS: The results showed that the number of hospitalizations attributable to diabetes are proportional to the "treated prevalence", all else constant, but that the more recent the OADs used (higher "vintage"), the lower are hospital admissions (p=0.03) and hospital costs (p=0.007). According to the model, if the average "vintage" of OADs had increased by one year, the number of admissions would have had a 3.8% reduction (3965 less episodes in 2009) and hospital costs would have suffered a 5.3% reduction (about 11 M€ in 2009). CONCLUSIONS: The possible influence of other difficult to quantify factors notwithstanding, our analysis suggests that in the last decade the availability of new OADs in the Portuguese market may have played a key role in the reduction of hospital costs and in-patient admissions attributable to diabetes.