The purpose of the handbook below is to promote the safe, coordinated and effective use of UAVs in a wide range of humanitarian settings. The handbook draws on lessons learned during recent humanitarian UAV missions in Vanuatu (March-April 2015) and Nepal (April-May 2015) as well as earlier UAV missions in both Haiti and the Philippines. The handbook takes the form of an operational checklist divided into Pre-flight, In-flight and Post-flight sections. The best practices documented in each section are meant to serve as a minimum set of guidelines only. As such, this document is not the final word on best practices, which explains why the handbook is available here as an open, editable Google Doc. We invite humanitarian, UAV and research communities to improve this handbook and to keep our collective best practices current by inserting key comments and suggestions directly to the Google Doc. Both hardcopies and digital copies of this handbook are available for free and may not in part or in whole be used for commercial purposes. Click here for more information on the Humanitarian UAV Network.