Oral cephradine, a new cephalosporin antibiotic whose structure is similar to that of cephalexin, was used to treat 53 episodes of urinary, bronchopulmonary and wound infections in patients presenting a disseminated cancer. Under these particular circumstances were 42% excellent responses, 21% favourable results and 37% bacteriological and clinical failures. The drug was particularly effective in treating infectoins in anatomically normal urinary-tract and wound infections. In vitro tests showed that cephradine inhibited most strains of PneumococcusStaphylococcus and Streptococcus pyogenes. The susceptibility to cephradine of Enterobacteriaceae was more variable. A zone of growth inhibition of 20 mm or more around a 30-μg cephradine disc was a good indication of drug sensitivity for most bacterial species tested. This study suggests that oral cephradine is a valuable alternative drug for the treatment of many bacterial infections that are usually treated by the oral route. Further studies should establish the optimal dosage of cephradine and compare this drug to other antimicrobial agents.