Social science research on the aims and impacts of Chinese development finance remains in its infancy because Beijing shrouds its overseas portfolio of grants and loans in secrecy. This chapter introduces the Tracking Underreported Financial Flows (TUFF) methodology that the authors have developed to assemble a comprehensive dataset of Chinese aid and debt-financed development projects around the globe. It also provides an overview of previous attempts to quantify Chinese development finance, and explains how the authors’ methods and data are different from those of others. This chapter also tests whether an alternative approach—field-based data collection—might yield more useful and reliable re- sults. Drawing upon evidence from a “ground-truthing” exercise in Uganda and South Africa, the authors demonstrate that field-based and TUFF-based data collection methods produce similar results. However, the TUFF methodology is less vulnerable to detection bias and more readily scalable than field-based data collection.