Objective To evaluate the Australian Capital Territory (ACT) Preterm Birth (PTB) Prevention Initiative and its effects on preterm and early term birth rates at the main tertiary hospital after 16 months of implementation. Design: A non-randomised before and after study, where the intervention was a multifaceted PTB prevention initiative. Setting: The main tertiary referral hospital in the ACT. Population: Women who birthed at the main tertiary hospital in the ACT in the pre and post intervention period. Methods: The PTB prevention initiative was implemented in 2019. Rates of early birth were assessed using run charts of bimonthly preterm and early term rates from 2014-2020. Main Outcomes measured: The main outcomes measured were rates of preterm and early term births before and after implementation of the PTB prevention initiative. Results: At the main tertiary hospital in the ACT, the rate of PTB was significantly reduced by 10% after 16 months of implementation of the initiative, corresponding to 45 averted or delayed PTBs. The number of iatrogenic early term births with no medical indication (NMI) was significantly reduced by 34.5% and resulted in 77 averted or delayed early term births. Conclusions: The multifaceted PTB prevention initiative safely lowered the rates of early birth in the ACT context. These results highlight the importance of prioritising early birth prevention, education, research and expanding the PTB Prevention Initiative nationwide.