The pharmacokinetics of Cefamandole was studied in 17 patients with terminal renal impairment, 10 of which were undergoing sessions of hemodialysis while 7 were in the period between dialysis sessions. An open two-compartment kinetic model was used to describe the bi-phasic decrease of the plasma concentrations of Cefamandole thus establishing the amounts of the antibiotic in the peripheral and central compartments together with the amount eliminated. All patients received an i.v. bolus injections of 15 mg/kg body weight. During the hemodialysis sessions, the pharmacokinetic parameters of Cefamandole were the following: alpha = 5.006 hr-1 beta = 0.182 hr-1 K12 = 2.598 hr-1 K21 = 2.147 hr-1 K13 = 0.441 hr-1 Vc = 5.700 l Vp = 6.190 l Vdss = 11.94 l It may be seen that there is a decrease in the overall elimination constant compared with that obtained during the periods between the dialysis sessions. A dosage regimen of multiple doses is established as a function of the pharmacokinetic parameters of the antibiotic for patients with terminal renal impairment undergoing periodic sessions of hemodialysis.