This brief synthesises knowledge gathered on the impact of age on prevalence of intimate partner violence (IPV) and the effectiveness of IPV prevention in low- and middle-income countries (LMICs) in seven interventions evaluated under the What Works to Prevent Violence Against Women and Girls Global Programme. The extent to which young women comprise a population more at risk of IPV, compared with older women, varies by geographical location and type of IPV. It is also likely that women and girls from different age groups respond to IPV prevention interventions in different ways; this may also vary according to geographical location, type of IPV, and intervention type. Nevertheless, the analysis presented in this brief suggests that young women are at greater risk of physical IPV than older women. Although younger women also appear to have experienced greater reductions in sexual and economic IPV than older women as a result of What Works interventions, there is no evidence to suggest that older women cannot, or do not, benefit from IPV prevention interventions.