The mhGAP Intervention Guide (mhGAP-IG) Version 2.0 for mental, neurological and substance use (MNS) disorders in non-specialist health settings, is a technical tool developed by WHO to assist in implementation of mhGAP. This updated version of the Intervention Guide is based on new evidence as well as extensive feedback and recommendations from experts in all WHO regions who have used mhGAP-IG Version 1.0.Beginning with general guidelines on “Essential Care and Practice”, the Intervention Guide includes a “Master Chart” which provides information on common presentations of the priority MNS conditions. This steers the clinician to the relevant modules which provide the framework for clinical assessment and management. While the target user group is non-specialized healthcare providers working at first- and second-level health-care facilities, the Intervention Guide is meant to be used as part of a systems approach involving health planners, managers and policy makers. The Guide therefore has separate module on Implementation so that the interventions proposed are supported by necessary infrastructure and resources.The mhGAP-IG Version 2.0 is an indispensable tool to scale up services for people with MNS conditions and their families.