The purpose of this document is to provide agencies with a guide with three tools containing key assessment questions that are of common relevance to all actors involved in Mental Health and Psychosocial Support (MHPSS) independent of the phase of the emergency. This guide will be useful for rapid assessments of MHPSS issues in humanitarian emergencies across sectors. The guide is designed for use by various humanitarian actors (governmental and non-governmental; local, national and global). It is based on the IASC Guidelines on Mental Health and Psychosocial Support in Emergency Settings (IASC, 2007). This document gives an overview of essential elements in performing MHPSS assessments that are: (a) relevant for all phases of the emergency (as defined by the IASC Needs Assessment Task Force (NATF)) and (b) generally applicable to all emergencies, whether large- or small-scale as well as to contexts with or without coordination through clusters. MHPSS needs assessments build on three types of information: (a) existing information collected through desk reviews; (b) collecting new information through assessments by MHPSS actors; and (c) collecting new information through integrating MHPSS questions in assessments by different sectors.