Eighty-five per cent of women sustain perineal trauma during vaginal birth. This may occur spontaneously or intentionally when a surgical incision (episiotomy) is made. The overall risk of obstetric anal sphincter injuries (OASIs) is approximately 2% of all vaginal deliveries. The morbidity associated with perineal trauma depends on the extent of injury, the suturing technique and materials, and the skill of the person performing the procedure. Therefore, it is important that focused and intensive training is available and that practitioners ensure that procedures, such as perineal repair, are evidence-based in order to provide care that is effective, appropriate and cost-efficient. In the UK, between 2000 and 2012, the OASIs rate in England tripled from 1.8% to 5.9%, suggesting that preventive measures need to be put in place. In this chapter, we highlight safe obstetric practice and preventative strategies based on the best available evidence to minimise perineal and anal sphincter trauma.