This article presents the results of heavy metals leaching from foundry waste deposited on two heaps from a Polish foundry. The foundry waste was stored there until the end of the 20^th century. The main components of the heaps included stored waste from molding and core sands, dust and sludge from dust collectors, refractory materials, parts from furnace linings, scrap, parts of graphite electrodes and other items. For several years, a portion of the stored waste was recovered and used for the production of road aggregate. Due to the fact that the exploitation of waste heaps and the disturbance of their structure could have a negative impact on the environment, research on the leachability of pollutants from stored waste was undertaken. In 2012-2017 waste samples from both heaps were regularly collected in order to assess the degree of leaching of heavy metals from wastes deposited at various periods. From the samples, the total content of heavy metals and their leachability were determined in accordance with the Polish standard. The research results showed that foundry waste does not have a negative impact on the environment, as the degree of metal leaching was low, and in most cases the permissible standards have not been exceeded.