Initially hailed as a miracle crop for biofuel production, Jatropha has recently attracted criticism for competing with food production, causing adverse biodiversity impacts, and jeopardizing land access by rural populations in tropical countries. This article analyzes the contested development of Jatropha biofuel sector in Tanzania by anchoring two new concepts of "organizational models" and "institutional arrangements" to the sectoral systems of innovation perspective. The notion of "organizational models" brings into relief the heterogeneity of actors in an innovation system and the ways in which the actors form networks, within and across national borders, to organize innovative activities. The concept of "institutional arrangements" refers to the ensemble of formal and informal institutions assembled during Tanzania’s colonial and postcolonial eras, which directly govern innovative activities in specific organizational models. Based on a location-specific and historically grounded institutional analysis within the innovation system framework, implications are drawn for the future development of Tanzania’s Jatropha sector including its links with European markets and for the regulation of "next-generation" biofuels.