World Health Organization’s (WHO) standard case management strategy for reducing ARI related mortality recommends oral cotrimoxazole and oral amoxicillin as first line drugs for the treatment of pneumonia. In 1989, the Pakistan Ministry of Health (MOH) adopted this strategy to control ARI mortality and recommended cotrimoxazole for treatment of outpatients pneumonia due to lower costs. A number of studies subsequently performed have shown significant in vivo and in vitro resistance of H. influenzae and S. pneumoniae, the commonest bacteria causing childhood pneumonia, to cotrimoxazole.