Thirty specialists in humanitarian work supporting the care and protection of children in crisis settings completed a 3-phase Delphi consultation. Proposals of best practice were elicited, reviewed, and rated by participants. A high level of consensus support was reached for 55 statements. These statements emphasized utilization of existing resources, participation, and inclusivity. The influences of resilience theory, social ecology, and cultural sensitivity were clearly evident. The utilization of developmental theory could be strengthened in relation to more differentiated understanding of the operation of protective influences and conceptualization of such influences in terms of “adaptive systems.” Wider research engagement by development scientists in diverse cultural settings and clear formulation of findings for practitioners and policy makers would further support evidence-based humanitarian practice.