Sulbenicillin, a wide broad spectrum penicillin, is active against a lot of gram positive and gram negative bacteria. The AA. studied the activity of this molecule against urinary infections causing germs, by evaluating two parameters: his antiadhesive capability and the Killing curves, in comparison with mezlocillin and piperacillin. An inhibition in adhesive capability of test-germs, due to sulbenicillin was obtained. Furthermore, resulting Killing curves showed more rapidity in action for sulbenicillin than for the two others molecules, versus resistant germs, like P. aeruginosa and S. faecalis.