Oral cefadroxil in doses of 0-6-1-8 g per day given on twice or three times daily schedules was effective in the treatment of thirty-six patients with infections such as abscesses, carbuncles, cellulitis, furunculosis and impetigo. Staphylococcus aureus strains and beta-haemolytic streptococci, alone or in combination, were cultured from lesions before treatment. In vitro studies with test discs showed that all the organisms were sensitive to cefadroxil, but twenty-three of twenty-nine S aureus strains and one of the seven streptococci strains were resistant to penicillin G. Pre- and post-treatment laboratory tests of renal, hepatic and haematopoietic functions produced no evidence of drug toxicity. The cefadroxil dosage effective in this study is lower than that recommended for currently available oral cephalosporins, which must be given on a four times daily schedule.