Much of the primary curative careprovided to the poor by the private sector occurs not atlarge hospitals but at small, single-person clinics. Whilesuch micro-health providers increase access, questionspersist about quality. Some have argued that themicro-health sector needs to be better regulated. This notecites recent studies in arguing that the micro-health sectorneeds to be better understood. A more evidence basedapproach may enable the World Bank Group to better targetinvestments and interventions and help these providersfulfill an important role serving the poor. The followingrecommendations are made at the conclusion of this paper:(1) Effort, rather than hardware or training, may count themost. (2) Scaling up interventions to improve qualityrequires understanding and addressing market failures. (3)Changing the way impacts are measured will lead to smarter investments.