This book represents the first comprehensive effort to analyze informal finance in Peru. We gathered data from a survey designed to capture formal and non-formal credit and savings transactions. We surveyed rural households, urban micro entrepreneurs, and wholesalers from three regions: Junin, La Libertad and Lima. Overall, we find high loan (65%) and savings rates (above 70%). Moreover, interestingly, while the number of non-formal credit transactions account for 81.5% of the total, they also represent 58.2% of the total loaned amount. As a result, average loans are significantly smaller in the non-formal sector (besides having shorter terms). The 48 case studies conducted to examine the anatomy of non-formal intermediaries show us the importance of the formal-informal financial linkage.