The focus of this paper is to understand what factors best explain the changing course of Tanzania’s policy on durable solutions for refugees, especially the changing approaches to naturalization and local integration from 2007 to 2012. To support this analysis, this paper adopts ‘process tracing’ as a methodology. As argued by George and Bennett, process tracing “attempts to trace the links between possible causes and observed outcomes” by drawing on “histories, archival documents, interview transcripts and other sources to see whether the causal process a theory hypothesizes or implies in a case is evident in the sequence and values of the intervening variables in that case.”7 In the absence of a testable theory of durable solutions from which hypotheses for the case of Tanzania may be derived, this paper argues that process tracing may be employed as a theory-building methodology by directing the systematic analysis of the factors that determined the particular course of policy development and implementation in a particular case study, which may then form the basis for comparisons with other case studies.