ABSTRACT: Despite progress, 2016 still saw 160,000 new infections and 120,000 AIDS-related deaths among children. Evidence gaps on how to best diagnose, treat, and deliver services to children living with HIV remain. A global research prioritization exercise was undertaken by WHO and CIPHER to focus research efforts in the context of diminishing resources.The Child Health and Nutrition Research Initiative methodology was adapted and used, as described by Irvine et al. Outcomes were reviewed by an expert group and 5 priority themes identified for testing, antiretroviral treatment, and service delivery, accounting for existing policies, published literature and ongoing research.A total of 749 questions were submitted by 269 individuals from 62 countries. For HIV testing, priority themes included strategies and interventions to improve access, uptake and linkage to care, including with novel diagnostic tools and entry points beyond antenatal care. For treatment, priorities included strategies to improve adherence, short- and long-term outcomes and management of coinfections, optimal drug formulations, and early ART. For service delivery, priorities included strategies or interventions to improve access, uptake and retention in care, including psychosocial and family support and approaches to HIV disclosure and reduction of stigma and discrimination.This is the largest Child Health and Nutrition Research Initiative exercise undertaken in HIV. The results provide guidance to focus future research in pediatric HIV for impact. Global commitment to support priority research, adequate investment, and strong leadership is urgently needed to improve the health and well-being of children living with and affected by HIV.