This special issue of JAIDS: Journal of Acquired Immune Deficiency Syndromes is devoted to health communication and its role in and impact on HIV prevention and care. The authors in this special issue have tackled a wide swath of topics, seeking to introduce a wider biomedical audience to core health communication principles, strategies, and evidence of effectiveness. Better awareness of health communication strategies and concepts can enable the broader biomedical community to partner with health communication experts in reducing the risk of HIV, sexually transmitted infections, and tuberculosis and maximize linkage and adherence to care. Interventions can be strengthened when biomedical and health communication approaches are combined in strategic and evidence-based ways. Several of the articles in this special issue present the current evidence for health communication's impact. These articles show how far we have come and yet how much further we have to go to document impact convincingly. Examples of the biomedical approaches to HIV control include treatment as prevention, voluntary medical male circumcision, preexposure prophylaxis, sterile needle exchange, opiate substitution therapy, and prevention of mother-to-child transmission. None will succeed without behavior change, which can be facilitated by effective health communication.