Discovering how to safely lower the rate of preterm birth needs to be one of the highest priorities in health care. One in 12 Australians is born preterm and in Aboriginals the rate is almost double. Recent research has provided evidence of how early birth may be avoided in some cases, but implementation at a population level has remained a challenge. Commencing in mid-2014, Western Australia (WA) embarked on a whole-of-population whole-of-state program with the singular aim of safely lowering the rate of preterm birth. The initiative is known as thewholeninemonthsTM and has included release of new clinical guidelines, an outreach program for all health care practitioners across the state, a public health campaign based on print and social media, and a dedicated new clinic at the tertiary level perinatal centre. Seven interventions were used including avoidance of non-medically indicated late preterm/early term birth, universal measurement of cervix length at all mid-pregnancy ultrasound scans and appropriate use of vaginal progesterone pessaries. In the first full calendar year (2015) the overall rate of singleton preterm birth in WA fell by 7.6% and was lower than in any of the preceding six years. Within the tertiary level centre the rate fell by 20% and the significant reduction extended down to the 28-31 week age group. State-wide, 200 cases of preterm birth were averted in that year, of which 45 would have been in the <31 week age group. The reduced rate of early birth was followed by a significant increase in the 39 week age group. These findings indicate the rate of preterm birth can be safely reduced at a population level by a package of interventions using existing knowledge. Our challenge now is to expand the effect and to apply the program to other populations.