Although on a case by case basis for pneumonia, in vitro resistance does not correlate very well with in vivo failures, nevertheless, clinical failure rate for pneumonia therapy has increased in Pakistan over the years. One can hypothesize that if bacterial pneumonia is a certain proportion of all pneumonia cases, the rise in clinical failures may be related to increasing antimicrobial resistance. Therefore, it is probable that this rising clinical failure rate could be a reflection of increasing resistance. There may be an increase in antimicrobial resistance of S. pneumoniae and H. influenzae to amoxicillin over the period of years and the rising treatment failure could be a reflection of the rising minimum inhibitory concentrations (MIC’s) (> 2 mcg/ml for H. influenzae, 1993-94), thereby, resulting in this increasing failure rate.