BACKGROUND:Long-active reversible contraceptives reduce unintended pregnancy and abortions, but uptake is low. Interventions to increase uptake in family medicine settings are untested. OBJECTIVE:The Australian Contraceptive ChOice pRoject, which was adapted from the successful US Contraceptive CHOICE study, aimed to evaluate whether a complex intervention in family medicine practices resulted in increased long-active reversible contraceptive uptake. STUDY DESIGN:This cluster randomized controlled trial was set in family practices in metropolitan Melbourne, Australia. From April 2016 to January 2017, we recruited 57 family physicians by mail invitation. Each family physician aimed to recruit at least 14 female patients. Eligible family physicians worked ≥3 sessions per week in computerized practices. Eligible women were English-speaking, sexually active, not pregnant, not planning a pregnancy in the next year, 16-45 years old, and interested in discussing contraception or in starting a new, reversible method. With the use of a randomization sequence with permuted blocks that were stratified by whether the family physician performed long-active reversible contraceptive insertion or not, family physicians were assigned randomly to a complex intervention that involved training to provide structured effectiveness-based contraceptive counselling and access to rapid referral to long-active reversible contraceptive insertion clinics. The 6-hour, online educational intervention was based on the US Contraceptive CHOICE Project and adapted for the Australian context. The control family physicians received neither the educational intervention nor access to the long-active reversible contraceptive rapid referral clinics and conducted their usual contraception counselling. We used the chi-square test, which was adjusted for clustering and stratification by whether the family physician inserted long-active reversible contraceptives, and binary regression models with generalized estimating equations and robust standard errors to compare, between the intervention and control groups, the proportions of women who had a long-active reversible contraceptive inserted. The primary outcome was the proportion of women with long-active reversible contraceptives that were inserted at 4 weeks. Secondary outcomes included women's choice of contraceptive method, quality of life, and long-active reversible contraceptive use at 6 and 12 months. Analyses were performed according to intention-to-treat. RESULTS:A total of 25 intervention and 32 control family physicians recruited 307 and 433 women, respectively (N=740). Within 4 weeks, 19.3% of women in the intervention group and 12.9% of women in the control group had long-active reversible contraceptive inserted (relative risk, 2.0; 95% confidence interval, 1.1-3.9; P=.033). By 6 months, this number had risen to 44.4% and 29.3%, respectively (relative risk, 1.6; 95% confidence interval, 1.2-2.17; P=.001); by 12 months, it had risen to 46.6% and 32.8%, respectively (relative risk, 1.5; 95% confidence interval, 1.2-2.0; P=.0015). The levonorgestrel intrauterine system was the most commonly chosen long-active reversible contraceptive by women in the intervention group at all time points. Differences between intervention and control groups in mean quality-of-life scores across all domains at 6 and 12 months were small. CONCLUSION:A complex intervention combination of family physician training on contraceptive effectiveness counselling and rapid access to long-active reversible contraceptive insertion clinics resulted in greater long-active reversible contraceptive uptake and has the potential to reduce unintended pregnancies.