The aim of the study has been to determine the effect of some substances such as dolomite, loam, compost, pinewood bark, peat, lime, charcoal, natural and synthetic zeoliteon reducing the impact of soil contamination with arsenic on the content of manganese in some plant species. The content of manganese in the test plants depended on the degree of soil contamination with arsenic, application of different substances as well as on the plant species and organ. Soil contamination with arsenic caused either an increase or a decreasein the content of manganese in plants depending on a plant species and organ. Inthe series without soil amending substances, in the arsenic contaminated objects the manganese content decreased in above-ground parts of cocksfoot and swede but increased in above-ground parts and roots of maize and yellow lupine, in roots of cocksfoot and swede and in straw and roots of spring barley. On the other hand, the highest rates of arsenic depressed the content of manganese in roots of cocksfoot, swede and spring barley. Addition of any of the aforementioned substances to contaminated soil changed the content of manganese in the plants. The most unambiguous effect of the different substances was determined in the case of above-ground parts of maize as well as above-ground parts and roots of cocksfoot, in which the manganese content fell down, and in roots of yellow lupine, grain and straw of spring barley, in which the content of manganese rose. Charcoaland loam caused the largest and synthetic zeolite led to the smallest changes in the content of manganese in plants.