The prevalence of Pneumocystis carinii was compared in two species of shrews, Sorex araneus and Sorex caecutiens in Finnish Lapland. The overall prevalence of P. carinii in S. araneus was 70% and in S. caecutiens was 17%. The prevalence for S. araneus is the highest reported for wild animals. The interspecific differences in prevalence were significant for all sex and age groups except for adult males. Based on multiway contingency tables (log-linear models), there was no dependence between sex or age of S. araneus and occurrence of P. carinii. In individual S. araneus the intensity of P. carinii was not related to the total number of helminths or the number of helminth species, and no dependence was observed between the presence of P. carinii and various helminth species.