The AA-HA! guidance aims to assist governments in deciding what they plan to do – and how they plan to do it – as they respond to the health needs of adolescents in their countries. It is intended as a reference document for national-level policy-makers and programme managers to assist them in planning, implementing, monitoring and evaluation of adolescent health programmes. After a brief introduction which summarizes the main arguments for investing in adolescent health, the document details the key steps from understanding the country’s epidemiological profile, to undertaking a landscape analysis to clarify what is already being done and by whom, to conducting a consultative process for setting priorities, to planning, implementing, monitoring and evaluating national adolescent health programmes, and ends with key research priorities (Figure A). It provides case studies to illustrate that what is being recommended can be done, and in some cases has already been done.