The kinetics (absorption, distribution and excretion) of carteolol were investigated after oral and intravenous administration to man, rats, Beagle dogs and rabbits. The half-life of carteolol in plasma was 1.22 approximately 1.45 hr in rats, 1.73 approximately 2.08 hr in dogs and 1.42 approximately 1.43 hr in rabbits, and was independent of the route of administration. The absorption rate constants, obtained from log(C1-C) approximately time plot, after oral administration were 1.89 hr-1 in rats, 1.04 hr-1 in dogs and 1.54 hr-1 in rabbits. There were no differences between tablet and film coated tablet in the pharmacokinetic parameters of carteolol in man after oral 30 mg (tablet or film coated tablet) administration [half life (t1/2)=4.50 hr (tablet), 4.30 hr (film coated tablet), elimination rate constant (k2) equals 0.154 hr-1 (tablet), 0.161 hr-1 (film coated tablet)]. The elimination rate constant, obtained from Sigma-minus plot after 2, 5 and 10 mg oral administration, was 0.137 approximately 0.160 hr-1.