Kinetic aspects of magnetically targeted drug transport are discussed. The influence of the magnetic drug carrier properties, the transported drug and the target organ parameters on the biological effect of the drug was investigated. A mathematical model reflecting mass transfer processes in the circulatory system was used for estimating the influence of these factors on the therapeutic effect of the drug delivered to the target. The nature of the effect of the drug release parameters, inactivation rate of the released drug in the blood and intensity of the carrier capture out of the target organ on the drug therapeutic action was revealed. Mathematical modeling of magnetically targeted drug kinetics was shown to provide prognostication of the drug effect and increasing of the experiment informative capacity.