Leucaena is widely recognized as the most sustainable, and valuable multipurpose tree legume in the tropics.It is a productive and profitable source of protein for ruminant production.Its other uses include: land regeneration; carbon sequestration and methane reduction; and biomass for paper pulp and electricity generation.Over the past three decades, scientists and farmers have greatly increased their knowledge of this plant, resulting in new plantings that have increased almost exponentially over time.As a consequence, there is demand for improved knowledge of the latest varieties, recommended management practices and feeding systems.This Issue of the Journal contains papers presented at a very successful International Leucaena Conference (ILC2018) including a pre-conference field tour, organized by The University of Queensland, staged from 29 October to 3 November 2018.The last dedicated conference on leucaena was held in Vietnam in 1997.Approximately 120 conference delegates from 12 countries, comprising researchers, extension officers, consultants, producers and students, shared their research knowledge and practical experiences regarding leucaena.Many excellent speakers exchanged information regarding how to plant, manage and use leucaena around the world.Engagement and networking ensured there was enthusiastic and fruitful discussion on future priorities and collaborative opportunities.The Conference especially honored Professor James Brewbaker from the University of Hawaii, for his lifelong contribution to the understanding of the genetics and breeding of the Leucaena genus, to teaching and research supervision of students from around the world and for his support of ILC2018.We acknowledge the help of many people, including members of the ILC2018 Organizing and Steering Committees and the Editorial panel who performed an important role in ensuring that submitted papers were of an acceptable standard.We especially thank the Editors of the Journal Tropical Grasslands-Forrajes Tropicales for their huge efforts in final reviewing, polishing and refining of manuscripts and ultimately preparing them for publication in the two issues of the Journal.