This paper relies on facilities and household survey data to estimate the ‘market share’ of faith-inspired institutions (FIIs) in the provision of health care services in Africa. While estimates based on facilities data, especially for hospitals, often suggest that the market share of FIIs is at 30 percent to 40 percent, estimates from household surveys are typically at less than ten percent. A number of potential explanations for these large differences are provided. Both types of estimates suffer from limits, but observing the two types of estimates alongside one other provides a more balanced view of the market share of FIIs in health care systems as a whole than is the case for any single type of measure.