Pyrobombus (Pyrobombus) lapponicus (Fabricius, 1793) and P. (P.) monticola (Smith, 1849) are described from type material. The male and worker are described of the former; the lectotype and a paralectotype (worker) are designated and in addition the male of P. monticola is described. Type studies of rondoui Vogt, 1909 and scandinavicus Friese, 1911, previously regarded as subspecies of P. lapponicus, revealed conspecificity with P. monticola. Furthermore, the subspecies hypsophilus Skorikov, 1912 and konradini Reinig, 1965 are also regarded as forms of P. monticola. The status of glacialis Schneider, 1902 is uncertain. P. lapponicus is distributed in northern Europe: Fennoscandia - eastwards in the northern parts of the USSR, while P. monticola exhibits a boreo-alpine distribution: Fennoscandia, eastwards on the Kola peninsula, the British Isles, Italy, the Pyrenees, the Alps and the Balkan mountains. In Fennoscandia P. lapponicus is found both in alpine/subalpine habitats and in adjacent coniferous forests, whereas P. monticola is restricted to alpine/subalpine areas. A comparative diagnosis of the two species, reinforced by drawings, is given. Metric studies of male abdominal sternite 7, hind basitarsus and position of ocelli on the vertex of queens were made to establish their diagnostic value. Some remarks on the biology of both species are also provided. The status of the Nearctic forms allied to P. lapponicus are discussed.