Sixty-six strains classified as P. verrucosum based on morphological criteria were characterized by RAPD analysis. Two groups could be identified which differed in their ability to produce ochratoxin A (OTA). Group I originating from proteinacious foods containing mainly high OTA producing strains, and group II originating from plants containing moderate to non-producing strains. The differences at the RAPD level are consistent with the recent reclassification of ochratoxin A producing penicillia to be either P. verrucosum or P. nordicum.