The agrarian transition, with its rapid growth in land-based investments, has radically altered agrarian and forest landscapes across the Mekong Region. These processes were enabled and accelerated by choices of actors in the public and private sectors with the aim of alleviating poverty and boosting socioeconomic development. We examine to what extent these goals were achieved and for whom, with a focus on poverty alleviation, gender equality, and forest conservation. Our descriptive assessment shows that the sustainability outcomes of the agrarian transition offer a highly variegated picture that is often not reflected in national level statistics used for monitoring the distance to target towards achieving the 2030 Agenda. Based on our findings, we sketch pathways for a more sustainable agrarian transition in the region. These pathways are explored in greater detail in three framing papers of the special issue "Agrarian Change in the Mekong Region: Pathways towards Sustainable Land Systems'.