Agricultural specialization is a complex multidimensional process, with multiple drivers and consequences. In this chapter specialization-focusing largely on an “Eastern European/North American” perspective-is discussed in the context of the related notions of agricultural intensification and agricultural concentration. The primary drivers of agroecosystem specialization, including mechanization, economies of size and scale, technological innovations, comparative advantage, market forces and “productionist” agricultural policies are described. Next, agricultural specialization is related to farms and farmland characteristics, notions of efficiency, and the geographic scale of specialization. The relations between multiscalar specialization and multiscalar ecologic simplification are outlined. Finally the consequences of specialization are assessed in terms of their potential ecologic and economic impacts on four key agroecosystem system properties: productivity, stability, persistence, and justice.