Three core samples from Lake Biwa, Japan, were analysed for mercury (Hg) and other heavy metals (iron, manganese, zinc, copper, lead, nickel, chromium, cobalt). The concentration of Hg in the core samples investigated varied from 106 to 222 ng/g. The sedimentary records of the lake indicate that the anthropogenic input of Hg parallels the increasing intensity of cultural activities in the lake basin. The maximum anthropogenic input could be identified for Hg during the mid-1960s. The geochemical data of the lake sediments are used to evaluate the behaviour of Hg with other trace metals.