OBJECTIVE: to provide an accessible list of individual and population-based risk factors associated with very preterm birth to assist care providers in planning appropriate pregnancy care. DESIGN: a population-based case-control study. SETTING: Victoria, Australia. PARTICIPANTS: women were recruited from April 2002 to 2004. Cases had a singleton birth between 20 and 31+6 weeks gestation and controls were a random selection of women having a birth of at least 37 weeks gestation in the same time period as the cases. MEASUREMENTS AND FINDINGS: structured interviews were conducted within a few weeks postpartum with 603 cases and 796 controls. Data were collected on sociodemographic factors; obstetric and gynaecological history; and maternal health problems, both pre-existing and occurring during the index pregnancy. Risk factors were calculated. KEY CONCLUSIONS: when correlated, risk factors were grouped as either lifestyle or maternal health factors. The majority of the risks were obstetric or gynaecological factors. Risks occurring in pregnancy may precipitate preterm birth. IMPLICATIONS FOR PRACTICE: knowing the risk factors for very preterm birth is likely to be helpful for pregnancy care providers. The development of a risk factor checklist based on the findings presented here may enable more informed planning of care and timely intervention.