Despite the considerable number of newer antibacterials made available over the past decades, amoxicillin, alone or in combination with clavulanic acid, still accounts among the most widely used antibacterial agents. Although they are often considered 'twin drugs', they are different both in terms of antibacterial activities and of safety profile. It is well documented that the clavulanate component may cause adverse reactions by itself, thus exposing patients to further, and sometimes undue, risks. Although amoxicillin/clavulanate should be considered as an alternative agent only for the treatment of resistant bacteria, evidence shows that it is often used also when a narrow-spectrum antibiotic would have been just as effective. This prescription habit may have serious consequences in terms of patients' safety, as well as in terms of the development of bacterial resistance.