ABSTRACTBy means of studies of lake sediment cores retrieved from Nicholson Lake, Vestfold Hills (68°35' S, 78°10' E), Antarctica, a climate chronology could be established, stretching from 6350 BP to the present. Climatic fluctuations were deduced on the basis of variations in organic and water contents, diatomic assemblage and wet bulk density with sediment depth. The chronology was based upon radiocarbon datings of sediment samples. Cool periods in the longer time-scale lasted from 4950 BP to 3230 BP and from 1300 BP to 250 BP, approximately, which were consistent with long-term fluctuations found elsewhere. Brief but more pronounced cold episodes occurred about 3650–3550 BP, 2950–2650 BP, 2300–2000 BP, 1300–1100 BP and 400–250 BP. Some of the cold events were similar in age with cold events occurring elsewhere, e.g. the 2300–2000 BP event.