Programs increasingly use community-based girl groups (CBGGs) to address risks and empower adolescent girls, but evidence on their impact is not always accessible to decision makers. A closer look at 30 CBGG programs in low- and middle-income countries found that CBGGs had the greatest reported success in improving health and gender attitudes and beliefs, while their effect on health behavior and status is mixed. Program implementers should consider CBGGs as a way to facilitate girls' empowerment, with complementary measures to engage community members and to promote enabling environments for greater program impact. Increased interest and investment in CBGGs should be supported by greater investment in further research to bolster the evidence base.