Evaluating the damage and health needs caused by a disaster is a critical function that should begin immediately after a disaster. A technical, objective approach will help decision-makers and, if necessary, guide the effective mobilization of appropriate humanitarian aid.

The post-disaster assessment should follow a pre-established plan that should be clearly defined prior to a disaster or emergency. Teams that conduct the assessments should have prior knowledge of the dynamics of disasters and the tools that are available for impact assessment. This article describes some of the best practices in conducting needs assessments.