This paper examines the impact of bank regulations, market structure, and national institutions on the cost of financial intermediation, measured by bank net interest margins and overhead costs. Using data from over 1,400 banks across 72 countries, the authors find that tighter regulations on bank entry and activities increase the cost of financial intermediation. Inflation also positively affects bank margins and overhead costs. While concentration is positively associated with net interest margins, this relationship disappears when controlling for regulatory impediments to competition and inflation. Bank regulations become insignificant when controlling for national indicators of economic freedom or property rights protection, while these institutional indicators robustly explain cross-bank net interest margins and overhead expenditures. The findings suggest that bank regulations reflect broader, national approaches to private property and competition, and that the impact of regulations cannot be isolated from these broader contexts.This paper examines the impact of bank regulations, market structure, and national institutions on the cost of financial intermediation, measured by bank net interest margins and overhead costs. Using data from over 1,400 banks across 72 countries, the authors find that tighter regulations on bank entry and activities increase the cost of financial intermediation. Inflation also positively affects bank margins and overhead costs. While concentration is positively associated with net interest margins, this relationship disappears when controlling for regulatory impediments to competition and inflation. Bank regulations become insignificant when controlling for national indicators of economic freedom or property rights protection, while these institutional indicators robustly explain cross-bank net interest margins and overhead expenditures. The findings suggest that bank regulations reflect broader, national approaches to private property and competition, and that the impact of regulations cannot be isolated from these broader contexts.