Strengthening disability inclusion in all phases of the project management will help the UN system to promote institutional accountability and learning, contributing to the implementation of the Convention on the Rights of Persons with Disabilities and the achievement of the Sustainable Development Goals (SDGs), particularly its commitment to the core value: leaving no one behind.  The disability-mainstreaming is promoted by the United Nations Disability Inclusion Strategy (UNDIS) launched by the Secretary-General in June 2019, as well as the ESCAP Disability Inclusion Policy launched by the Executive Secretary in 2020.  To translate the concepts and principles contained in these documents into reality,  the Guidance Note lays out core principles and practice steps to be taken to mainstream disability perspectives at all stages of project management: planning; implementing; monitoring and evaluation.  The Guidance Note aims to support project managers in integrating disability inclusion into the design of projects.