Armillaria sp. are widespread wood decomposing and pathogenic fungi that spread in the soil by root-like fungal structures named rhizomorphs. We investigated the effect of heavy metals on the production of Armillaria rhizomorphs and the extent of absorption of heavy metals into the rhizomorphs. A. ostoyae and A. cepistipes were inoculated into the soil of model ecosystems that were subjected to four treatments a) control without added heavy metals, irrigation pH 5.5. b) heavy metals dust resulting in: Cu, 640 mg/kg; Zn, 3000 mg/kg; Cd, 10 mg/kg; Pb, 90 mg/kg in the top soil. irrigation pH 5.5. c) acid irrigation pH 3.5 imitating acid rain. d) the combination of acid irrigation and heavy metals. The treatments had no effect on rhizomorph production, assessed by rhizomorphs length and dry weight in soil core samples. In the rhizomorphs produced by the Armillaria species over a period of three years, the concentration of Cu, Zn and Cd, but not Pb was significantly higher in soils with added heavy metals than those without. In the contaminated soils, the mean concentrations of heavy metals in the rhizomorphs were 228 mg/kg Cu, 6300 mg/kg Zn, 10.6 mg/kg Cd, and 12.1 mg/kg Pb. Energy dispersive X-ray (EDX) microanalysis showed that Zn was preferentially absorbed to the melanized cortex of the rhizomorphs. The results showed that Armillaria rhizomorphs can bind considerable amount of heavy metals and thus may contribute to the stabilization of heavy metals in the soil.