The boron contents of 68 edible common macrofungi of Hungary were analysed. The average boron content of the examples was 11.74 mg/kg dry mass, this is higher than the average value of green plants of Hungary (7.4 mg/kg dry mass). Although the highest boron contents were found in the examples from woods near Budapest, the differences between the various sites are not significant. It seems that the site has not an important effect on the boron content of mushrooms. Some taxonomical groups are examples of higher, others are examples of lower boron content. The highest concentration of boron (54.3 mg/kg dry mass) was found in the species Marasmius wynnei which indicates a bioconcentration of four to five fold to the average boron level. Significant bioaccumulation of analysed edible species was not established, but the poisoning mushroom Mycena pura has a very great (401-607 mg/kg dry mass) boron concentration. This accumulation is observed to the first time.