This paper reviews the evidence on sexual and reproductive health and rights (SRHR) of adolescent girls in low-income and middle-income countries (LMIC) in light of the policy and programme commitments made at the International Conference on Population and Development (ICPD), analyses progress since 1994, and maps challenges in and opportunities for protecting their health and human rights. Findings indicate that many countries have yet to make significant progress in delaying marriage and childbearing, reducing unintended childbearing, narrowing gender disparities that put girls at risk of poor SRH outcomes, expanding health awareness or enabling access to SRH services. While governments have reaffirmed many commitments, policy development and programme implementation fall far short of realising these commitments. Future success requires increased political will and engagement of young people in the formulation and implementation of policies and programmes, along with increased investments to deliver at scale comprehensive sexuality education, health services that are approachable and not judgemental, safe spaces programmes, especially for vulnerable girls, and programmes that engage families and communities. Stronger policy-making and programming also require expanding the evidence on adolescent health and rights in LMICs for both younger and older adolescents, boys and girls, and relating to a range of key health matters affecting adolescents.