Preliminary data indicate that the peritoneum is not a significant barrier to diffusion of gentamicin. Peritoneal clearance is low and probably will fall within the range of 5–10 ml/ min, similar to that of kanamycin. The rate of removal of gentamicin by peritoneal dialysis appears to be fairly constant and averages slightly less than 5l0 µg/hr. It is predicted that approximately 20% of the administered dose can be removed in 36 hr by peritoneal dialysis of anuric patients. In patients with normal renal function, the amount of gentamicin removed by dialysis would not significantly add to the normal mechanism for disposal of this drug under physiologic circumstances.