OBJECTIVE: To compare the rates of attempted and successful instrumental births, intrapartum cesarean delivery, and subsequent perinatal and maternal morbidity before and after implementing a training intervention to arrest the decline in forceps competency among resident obstetricians. METHODS: This retrospective cohort study examined all attempted instrumental births at Monash Health from 2005 to 2014. We performed an interrupted time-series analysis to compare outcomes of attempted instrumental births in 2005-2009 with those in 2010-2014. RESULTS: There were 72,490 births from 2005 to 2014 at Monash Health, of which 8,789 (12%) were attempted instrumental vaginal births. After the intervention, rates of forceps births increased [autoregressive integrated moving average coefficient (β) 1.5, 95% confidence interval (CI) 1.03-1.96; P<.001], and vacuum births decreased (β-1.43, 95% CI-2.5 to-0.37; P<.01). Rates of postpartum hemorrhage decreased (β-1.3, 95% CI-2.07 to-0.49; P=.002) and epidural use increased (β 0.03, 95% CI 0.02-0.05; P<.001). There was no change in rates of unsuccessful instrumental births (β-0.39, 95% CI-3.03 to 2.43; P=.83), intrapartum cesarean delivery (β-0.29, 95% CI-0.55 to 0.14; P=.24), third- A nd fourth-degree tears (β-1.04, 95% CI-3.1 to 1.00; P=.32), or composite neonatal morbidity (β-0.18, 95% CI-0.38 to 0.02, P=.08). Unsuccessful instrumental births were more likely to be in nulliparous women (P<.001), less likely to have a senior obstetrician present (P<.001), be at later gestation (P<.001), and involved larger birth weight neonates (P<.001). CONCLUSION: A policy of ensuring obstetric forceps competency before beginning vacuum training results in more forceps births, fewer postpartum hemorrhages, and no increase in third- A nd fourth-degree perineal injuries or episiotomies.