The yearly differences between material collected over two years by means of pitfall traps in three peat bogs in Lithuania and one in Finland were analyzed. Single year collections formed 58.8–87.9% of all the species collected over the two year period. No turnover occurred in the abundant species (> 1% of all specimens in one year sample) if traps were not relocated. The rates of the turnover can vary considerably in various dominance groups and show different trends at different sites. Marked annual differences in abundance were recorded even among some typically abundant peat bog species like Pardosa sphagnicola, Drassyllus pusillus, Scotina palliardi, Agyneta cauta, Arctosa alpigena, Bathyphantes gracilis, Antistea elegans, and Drassodes pubescens. Only a few species typical of other habitats were found to be permanently abundant in peat bogs. Five species recorded during the investigation are new to the spider fauna of Lithuania.