Abstract: A new species belonging to the family Boletaceae Chev. (Agaricales) is described: Suillus lapponicus Harmaja. It is fairly closely related to S. variegatus (Fr.) Kuntze, from which it differs mainly in the decurrent hymenophore, slightly wider pores, somewhat darker KOH reaction of the pileus surface and context, larger spores, slightly darker spore wall which becomes red-brown in KOH, and the presence of two kinds of pleurocystidia, both differing from those of S. variegatus. S. lapponicus is known from one locality in Finnish Lapland, from dry heath forest, apparently forming an ectotrophic mycorrhiza with Pinus sylvestris L. Carminophilic basidial granules and spore wall are reported in S. lapponicus.