The studies on the accumulation of toxic effects of TOX and DOX have been carried out with the Kagan and Stańkiewicz method. For 7 months the rats were intragastrically administered, with a tube, 20% water solutions of TOX and DOX at 1/10, 1/40 and 1/80 DL50 doses; in addition, for 4 months they were given 100% DOX at 1/10 DL50 doses; Within the experiment, the animals' mortality, appearance and behaviour were observed and once a month their body weight was determined. After the exposure, haematological and biochemical studies along with the dissection determining the weight of some internal organs were carried out. The intoxication symptoms were found mainly in the animals obtaining DOX at the 1/10 DL50 dose. They were manifested by reduced body weight gain, slightly reduced activity of whole blood acetylcholinesterase and disturbed body equilibrium, weakly marked arched back, hypokinesis, slightly weakened muscular force and slight paresis of hind legs. On the other hand, the mortality rate did not show accumulated toxic effects for TOX and DOX.