Rapid population growth in agroecologies that are already under high population pressure poses a major challenge for development policy. It becomes an even greater challenge in complex agroecologies where little new technology for rapid agricultural expansion is available. The mountain zones of the Zaire-Nile Divide in Central Africa present an example of such a challenging environment where agriculture has encroached onto marginal zones, that is, water catchment areas and the last tropical forests of the area. This study by von Braun, de Haen, and Blanken highlights the potentials of agricultural development for the employment, income, and consumption of the poor, but also stresses that nonagricultural rural growth and employment expansion are key to improved food security and nutrition in this setting. The authors show that the delivery of public goods—health services, sanitation, and education—has to move ahead in order to maintain and improve the human capital foundation in this stressed environment. The study is based on detailed primary household data utilized in innovative ways to assess the household's and farmer's (and her husband's) behavior in the subsistence economy vis-a-vis options for specialization. A number of interesting policy findings emerge, such as the poor being too poor to capture the gains from efficient specialization because they need to take care of subsistence-based insurance against hunger. While generally favorable effects of commercialization of agriculture for nutrition are manifested by this study and preceding IFPRI studies on this topic, the present study also draws attention to the need for concern about land tenure when the stimulus for agricultural commercialization is given in a land-scarce environment.