In the literature on the religious contribution to health and development, it is commonly stated that faith-inspired institutions (FIIs) provide from 30 to 70 per cent of all health care provision in Africa. This article tracks the sources of such statements back to the 1960s, highlighting a process of ‘broken telephone’ whereby estimates are passed on and frequently distorted by policy- and advocacy-oriented influences at both the national and international levels. This demonstrates how estimates are being wielded bluntly, often resulting in poorly substantiated claims to the detriment of more careful research, thereby weakening the empirical knowledge-base and improved practice.