Simple SummaryModern varieties of cereal grains commonly cultivated in Europe are considered good alternative energy sources that can be used as partial replacements for barley and wheat, which are commonly used as primary energy sources in pig feed. In Central Europe, rye deserves special consideration as it can be cultivated on low-fertility soils with a very low environmental impact among cereals. The objective of the present study was to evaluate the effect of partial substitution of wheat and barley with maize or modern rye varieties (population and hybrid) on concentration of selected heavy metals in feed offered to pigs and in pig muscles, liver and kidneys at slaughter.The carry-over of heavy metals from feed to muscles is generally low if animals are fed with a standard diet containing amounts below the maximum permissible levels. However, prolonged exposure to heavy metals can lead to their accumulation in some organs like muscles, liver, and kidneys. This paves the way for human health risks related to the consumption of products of animal-origin. Thus, using feed mixtures with a low level of heavy metals in pig production will contribute to increasing public health and safety and is of environmental concern. The study aimed to assess the impact of the level of some heavy metals (Cd, Pb, Hg, Cu, Zn, Fe and Mn) in standard (control) feed mixtures and in alternative feed mixtures based on maize or new rye varieties (population and hybrid) on the heavy metal concentration in muscles, liver and kidney of fattened pigs at slaughter. While some differences between heavy metals content in examined tissue samples from experimental groups were observed, all of them were in the range of allowable levels according to European Community rules. In conclusion, new rye varieties, especially the hybrid variety, could be an alternative source of cereal grains for pig nutrition.