Critical loads of lead (Pb), cadmium (Cd) and mercury (Hg) were calculated and mapped with respect to drinking water protection in agricultural areas of the Crimea. In accordance with the ICP modelling and mapping manual, the calculation of critical loads was based on an effect-based approach, accounting for the possible negative influence of heavy metals on the biota at defined critical concentrations in the soil solution. The calculations of critical loads of Pb and Cd were based on a simplified mass balance for the metals in a 30 cm thick soil layer under the prerequisite that the airborne input of heavy metals into the agricultural ecosystem must not exceed the total fluxes of these metals from the system. For Hg a soil depth of I m was considered. As a large part of the agricultural areas in the Crimea is in the northern territories, where mainly wheat and other cereals are grown, the potential plant uptake of metals by these cultures was taken into account. Based on the results of the calculations, the Crimea could be subdivided into sensitive regions with critical loads of up to 10.2 g ha^-1 a^-1 Pb, 3.16 g ha(-1) a-1 Cd, and 1.02 g ha(-1) a^-1 Hg, and less sensitive regions with critical loads that are up to two times (Pb, Cd) or three times (Hg) lager.