The chemical, physical, kinetic features, spectrum and clinical employment of amoxicillin (alpha-amino-p-hydroxbenzylpenicillin) are described. A kinetic study on 48 volunteers indicated its rapid gastroenteric absorption. In addition, the new drug quickly reached serum levels that were able double those obtained with corresponding ampicillin doses of equal weight. A very satisfactory therapeutic response and no more than trivial side-effects were noted in a clinical trial on 106 patients, most of whom presented bacterial infection of the upper and lower airways.