The lichen genus Lepraria in Poland, comprising 17 species, is reviewed: for each taxon, remarks on the chemistry, distribution and habitat preferences are provided. Distribution maps are also presented, together with a key for determination of the Polish species. Lepraria diffusa var. chrysodetoides is reduced to a synonym of L. diffusa s. str., a new chemotype with a new substance is reported for L. neglecta, and rangiformic acid is reported for the first time for chemotype III of L. caesioalba. Lepraria borealis is reported for the first time from Africa (Canary Islands) and L. nigrocincta from Nepal.
