A new nitroimidazole derivative, N-(5-carboxy-5-amino pentane) carbamic ester of 1(2-hydroxyethyl)-2-methyl-5-nitroimidazole (APMN), was administered to rats by the following routes: i.p. and orally (100 mg/kg); i.m. (100 and 250 mg/kg). Plasma kinetics of the drug fit a monoexponential function with a half-life of 0.5 h and a volume of distribution of 555 ml/kg. In tissues the peak levels of the drug (at 0.5 h) were 700, 150 and 40 micrograms/g in kidney, liver and heart respectively and their disappearance rate was similar to that observed for plasma. Urinary excretion of the unmodified drug in 23 h was less than 30% of the administered dose. No APMN was found in plasma and urine after oral administration.