Recent global malaria control initiatives highlight the potential role of drug retailers to improve access to early effective malaria treatment. We report on the findings and discuss the implications of an educational programme for rural drug retailers and communities in Kenya between 1998 and 2001 in a study population of 70 000. Impact was evaluated through annual household surveys of over-the-counter (OTC) drug use and simulated retail client surveys in an early (1999) and a late (2000) implementation area. The programme achieved major improvements in drug selling practices. The proportion of OTC anti-malarial drug users receiving an adequate dose rose from 8% (n = 98) to 33% (n = 121) between 1998 and 1999 in the early implementation area. By 2001, and with the introduction of sulphadoxine pyrimethamine group drugs in accordance with national policy, this proportion rose to 64% (n = 441) across the early and late implementation areas. Overall, the proportion of shop-treated childhood fevers receiving an adequate dose of a recommended anti-malarial drug within 24 h rose from 1% (n = 681) to 28% (n = 919) by 2001. These findings strongly support the inclusion of private drug retailers in control strategies aiming to improve prompt effective treatment of malaria.