The land tenure crisis has reached Africa, leading to insecure tenancy, landlessness, resource rights conflicts and less investment in appropriate agricultural technology. This study analyzes the interrelation between land tenure and technological change and their contributions to sustainable agrarian and rural development. The research approach is based on New Institutional Economics and interdisciplinary fieldwork in Togo, Benin, Cameroon and Sudan. In summary, the emerging informal, non-registered private tenure systems neither have impeded technological change nor have they been an obstacle to access to credit whereas common property has been severely eroded and undermined by institutional and technological change. However, these dynamics actually give African nations an opportunity to start or to proceed with far reaching institutional and legal reforms and the re-formulation of a coherent land policy.