This special issue of the Bulletin on Narcotics is part of a broader process that the United Nations Office on Drugs and Crime (UNODC) has undertaken to develop a thematic field of research on alternative development. It elaborates on the thematic chapter of the World Drug Report 2015 by showing in more detail the evolving debate around alternative development and the new ways in which it is implemented in practice. The World Drug Report 2015 documented how alternative development interventions have evolved over the years, reaching a multidimensional approach beyond the single focus on reducing illicit drug cultivation, while recognizing that adequate funding and political support bring the long-term socioeconomic and environmental development needed to sustain the reduction of income from illicit crops. The country case studies presented in this special issue show that there are opportunities to improve alternative development and come up with more sustainable solutions, but they also highlight how complex the local contexts can be in areas where alternative development is implemented. While there can be no single blueprint for successful and sustainable alternative development interventions, this issue of the Bulletin on Narcotics shows how alternative development can be most effective, how it can be better integrated within broader development and governance efforts, and how it can be linked more strongly to the 2030 Agenda for Sustainable Development and the Sustainable Development Goals.