The authors carried out a pharmacokynetic study on the Bulgarian preparation Tempidone in rats. They examined resorption, distribution and excretion of the preparation in urine, bile and feces of rat after venous and oral administration. The experiments were carried out on 207 white male rats of the Wistar strain, weighting from 160 to 180 gm. Blood samples were obtained at various intervals from the onset of venous administration of the preparation in a dose of 100 mg/kg of body weight. After oral administration of the dose of 125 mg/kg of body weight in addition to blood samples other samples from brain, liver, stomach and intestines (small and large) were obtained as well. Excretion of Tempidone through the bile was examined after intraperitoneal administration of 250 mg/kg of body weight. They proposed pharmakynetic models after venous and oral administration of Tempidone. The obtained results gave evaluation for the rate, with which the distribution processes in the organism of rats occurred. Pharmacologic action of Tempidone coinceded in time with the creation and support of effective plasma concentrations. The wide distribution and preservation of Tempidone in the tissues suggested that it underwent the so called tissue binding.