The identification of the European pine species often used as ornamentals (Pinus nigra, P. sylvestris, Pinus halepensis, Pinus brutia, Pinus leucodermis, Pinus maritima, Pinus peuce, Pinus pinea, Pinus cembra, Pinus mugo, Pinus sibirica), belonging to the two subgenera Strobus - Haploxylon (Pinus peuce, Pinus sibirica and Pinus cembra) and Pinus - Diploxylon (Pinus nigra, Pinus sylvestris, Pinus halepensis, Pinus brutia, Pinus leucodermis, Pinus maritima, Pinus pinea, Pinus mugo), was investigated by isozyme gene markers of malate dehydrogenase (MDH) and menadione reductase (MNR) enzyme systems. Two loci (MDH-B and MDH-E), from the MDH enzyme system and one (MNR-A) from the MNR were used. Of the two subgenera (Pinus and Strobus), the subgenus Strobus was characterized by: a) presence of MDH-A locus, b) presence of MDH-E2 allele (from moderate to high frequency) and c) by monomorphic phenotype at MNR-A2 allele. In each subgenus one pine species was discriminated from the others, either by the existence of unique alleles or by the great variation in allele frequencies.