Introduction: Second-line pharmacotherapy for Type 2 Diabetes Mellitus (‘diabetes’) is necessary for optimal glycaemic control and preventing longer-term complications. We aimed to describe temporal trends in, and associations of, Australian general practitioner (GP) registrars’ prescription, and initiation, of ‘new’ second-line oral agents (dipeptidyl peptidase 4 inhibitors, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide 1 agonists) compared to sulphonylureas. Materials and methods: A longitudinal analysis (2010–2018) of data from the Registrar Clinical Encounters in Training project. Analysis included any diabetes problem/diagnosis that involved prescription of sulphonylureas or ‘new’ oral agents. Simple and multiple logistic regression models were fitted within the generalised estimating equations framework. Results: 2333 registrars recorded 6064 diabetes problems/diagnoses (1.4%). 835 problems/diagnoses involved sulphonylurea or ‘new’ medication prescription. Of these, 61.0% [95% CI:57.4–64.4] involved ‘new’ medication prescription. 230 problems/diagnoses involved sulphonylurea or ‘new’ medication initiation, with 77% [95%CI:70.8–82.1] involving a ‘new’ medication. There was a significant 52% per year increase in prescribing (OR = 1.52[95% CI:1.38–1.68],p<0.001), and a 77% per (two-to-three-year) time-interval increase in initiation (OR = 1.77,[95% CI:1.30–2.43],p = <0.001) of ‘new’ medications compared to sulphonylureas. ‘New’ medications were prescribed less for non-English-speaking patients. There was some regional variation in prescribing. Conclusion; Registrar uptake of ‘new’ oral agents compared to sulphonylureas has increased rapidly.