The dietary structure and distribution patterns in pine martens Martes martes in situations of different food supply in the coniferous forest of north-eastern Belarus were investigated. A total of 1222 scats were analysed, and snowtracking of pine martens was done each winter. Seven pine martens were radiotracked (n=7549 radiolocations). Abundance of the main prey was monitored. The pine marten acts both as an active predator, mostly taking many species of rodents and birds, and as a gatherer, feeding on fruits and scavenging for carrion. In the ecologically poor woodland on sandy soil the predator specializes in feeding on carrion in the cold season, and on berries in the warm season. The richer food supply in the woodland on clay soil results in a markedly higher population density and fairly even distribution of pine martens than those in the woodland on sandy soil, where pine martens mainly live in valley habitats. The winter density of bank voles drives the pine marten numbers. Also biomass of carrion is a crucial factor determining the predator density by late winter.