Background Diabetes education is believed to bring about sustained benefits in diabetes mellitus (DM) patient outcomes. These benefits have not been widely studied in an inpatient hospital setting, and as such the aim was to determine whether a hospital diabetes in-service, and specifically diabetes education, results in reduced blood glucose and HbA1c levels after hospital discharge. Methods and materials A cohort review was performed at a large teaching hospital, in Canberra, Australia. Sixty seven patients comprising 35 males and 32 females who were referred upon discharge to the Diabetes Services as having a history of uncontrolled DM from February 1st 2015 until January 31st 2016 were evaluated. The retrospective discharge blood glucose level (BGL) was compared to prospective BGL 3 months after hospital discharge. HbA1c was prospectively taken before and 3 months after Diabetes Service education. A between subjects t-Test was used to compare patients’ glucose and HbA1c averages. Results The average discharge BGL result was 13.3 mmol/L, compared to the post-discharge result of 11.2 mmol/L, indicating a significant decrease (p = < 0.01). The average pre-HbA1c result was 10.45%, and decreased to the post-HbA1c result of 8.96%, which was significant (p = <0.05). Conclusion This study is the first to measure the direct glucose adherence benefits associated DM education within Australia and provides evidence on the effectiveness of a Diabetes Service in reducing patient BGLs. Utilisation of Diabetes Services to control glycaemia encourages ongoing efforts and translates to reduced micro and macro cardiovascular risk factors associated with DM.