Changes in glacioclimatic conditions on Spitsbergen during the Upper Holocene are described on the basis of a combined analysis of the botanical, mineral and spore‐and‐pollen composition and of the absolute dates of two fossil peat deposits in Adventdalen and Linnedalen. Three climatic phases may be distinguished during the Subboreal period: a cool phase followed by a warmer phase and then by a further cool phase; during the first half of the Subatlantic period one may identify a warming with greater precipitation. The cool phases of the Subboreal period coincide with radiocarbon datings of glacier advance stages on the archipelago, namely the Passdalen at about 4500 years B.P. and the Gronfjorden stage at about 3000–2500 years B.P.