AbstractEconomic theory and agroecosystem analysis were used to assess the effects of technological changes on deforestation during the 20th century in the miombo savanna woodlands of northern Zambia. Historical facts concerning demographic, policy and technological changes are combined with applied farm household models to illustrate how these changes affected typical land users in the area. Two major technological changes are highlighted: the introduction of cassava during the first half of the century (initially within the chitemene shifting cultivation system) and the expansion of fertilized maize systems in the late 1970s. It is concluded that the most significant technological change in the region during the 20th century was the introduction of cassava. It represented a labour- and land-saving technological change, which also made production less risky. It reduced short-run deforestation but at the same time facilitated population growth and concentration.