Agricultural research-and-development (R&D) systems generate and disseminate new technologies, aiming to enhance crop and livestock production sustainably. Adoption-impact studies analyze farmer acceptance of these innovations and their impacts to identify what was taken up, how it works in farmers’ fields, and the implications thereof. In this paper, we focus on adoption-impact studies in wheat agri-food systems in the Global South and review 47 empirical studies published during 2008–2017. The review focuses on the assessment of technological changes rather than the nature of these changes per se. We document the breadth and adequacy of empirical approaches and methodologies, as well as the diversity and coverage of thematic areas for adoption-impact analyses. The coverage and scope do not fully capture the complex and dynamic technological changes taking place in wheat systems. The reviewed studies typically conceive the adoption process as a dichotomous choice representing the replacement of old inferior practices with new superior ones. Most reviewed impact studies address only the short-term changes associated with innovation adoption on yield and profitability, often assuming that improvements in the living standards of farm households follow de facto. Labor productivity and the ecological and social impacts of technological innovations were largely ignored. We propose several directions to enhance both data availability and analytical rigor, and to reorient future research toward the less-explored but socially, economically, and ecologically relevant topics.