The objective of this thesis is to gain insights into factors affecting commercialization of dairy farming under land scarcity, through assessment of the dynamics of market participation, land use intensification, and resilience of dairy farming systems in relation to the markets for inputs, services, and outputs. The main research question addressed is: in what ways do market quality and spatial factors affect commercialization of dairy farming systems under land scarcity in two countries in the East African highlands? The study resulted in three empirical chapters and a systematic literature review. Main conclusions include: that spatial factors are critical drivers of commercialization of dairy farming, with proximity to local input and output markets and being located in a dairy cluster enhancing commercialization; that concurrent and co-dependent upgrading in farming, market, and context domains enhances market quality for dairy and/or other farming activities; that farmers’ market quality and feasibility space are also enhanced by the plurality and performance of input and service provision; and that risks and risk perceptions around market quality play important roles in decisions of upgrading, especially around system jumps. Connecting theory around system jumps of farming systems with theory on resilience determinants offers a way to understand farmer attitudes toward commercialization. Dairy commercialization will thus need to consider spatial effects, concurrent upgrading in farm, market, and contextual domains, plurality and performance of input and service providers, risks and risk perceptions, and resilience, if commercialization is to be sustained over time.