Motivation: Despite increasing research on the United Nations' 2030 Agenda and its 17 Sustainable Development Goals (SDGs), there is a lack of attention to the role of political institutions in localizing the SDGs. By exploring localization of the 2030 Agenda in a concrete political context, we go beyond prior research that mainly studies interlinkages and discourses underpinning the agenda. Purpose: This article explores political qualities of localization processes through three analytical concepts that bring such qualities to the forelegitimacy, responsibility and accountability. We investigate localization attempts with regard to the 2030 Agenda in Tanzania, aiming to identify drivers and obstacles of localization. Approaches and Methods: The article provides an explorative case study based on policy document review and 28 semi-structured interviews with civil servants, parliamentarians, representatives from civil society organizations, the UN and other international agencies in Dar es Salaam and Dodoma between 2017 and 2019. Findings: Elements of localization are policy alignment at the national level, work with statistics and indicators, and awareness creation among a variety of actors. Drivers of localization are the government, civil society organizations, the UN, members of parliament and demands for review at the UN High-level Political Forum. Obstacles to localization are unclear allocation of responsibility, insufficient coordination , high turnaround of people in key positions, a lack of data availability, low awareness of the SDGs among citizens, a shortage of resources and shrinking democratic space. Policy Implications: We posit that a clear allocation of responsibility facilitates implementation and ensuing accountability measures. For localization to occur, knowledge of the SDGs must reach beyond a limited circle of elites. Moreover, it is important to acknowledge that sustainable development is a politically charged field. Political institutions at all levels should therefore be central arenas for debating and adopting the 2030 Agenda as part of its localization.