Cefoselis sulphate is a new parenteral cephalosporin, which was launched into therapy in Japan on 9 September, 1998, under the brand name Wincef. Cefoselis sulphate, like all the other beta-lactams, exhibits its bactericidal eff ects by binding to penicillinbinding proteins. It has a spectrum of activity that covers aerobic and anaerobic gram-positive and gram-negative bacteria. Cefoselis sulphate has been approved to treat infections caused by Staphylococcus and Pseudomonas especially respiratory and urinary tract infections. The recommended dose of cefoselis is 1 g twice a day as an intravenous infusion. The duration of therapy is from 5 to 14 days. Cefoselis sulfate has a potent antibacterial activity against Gram-positive bacteria involving Staphylococcus, Pneumococcus, and Streptococcus, as well as Gram-negative bacteria involving Pseudomonas, Escherichia coli, Klebsiella, Enterobacter, Serratia, Proteus, Morganella, and Providencia.