The levels of variation and genetic diversity of offspring of randomly selected old mother trees in four marginal populations of the Pinus cembra in the Tatra Mountains were analyzed. Twenty-four isozyme loci were analyzed (nine of them were monomorphic). The analyzed offspring of Swiss stone pine showed highly diverse polymorphism at the levels of both provenances and individual families (the offspring of one mother tree). The mean observed heterozygosity was low and very similar to that of other Carpathian populations. The genetic diversity (mean Fst = 11%) between the four provenances was higher than that observed for populations from the Carpathian Mountains and the Alps. The genetic uniqueness (high genetic richness and diversity) of the analyzed Tatra populations of P. cembra as a whole and particular tree stands requires protection because of their valuable contribution to the species total genetic diversity (gene pool).