For successful transformation of prototrophic industrial yeast strains dominant selectable markers are necessary. In the present study we show the applicability of a selection system based on the phenotype of multidrug resistance. The mutant pdr3-9 allele on centromeric or episomal vector, encoding a more efficient transcriptional activator with Y276H amino acid substitution, was used as a dominant selectable marker for selection of transformants. The pdr3-9 allele conferred resistance of transformed cells to cycloheximide, chloramphenicol, mucidin and oligomycin both in the absence and in the presence of a chromosomal copy of the PDR3 gene. Both multicopy YEp352/pdr3-9 and centromeric pFL38/pdr3-9 vectors bearing the mutant pdr3-9 allele have proved to be a valuable tool for a direct selection of transformants of industrial strains of Saccharomyces cerevisiae.