Prunus spinosa, blackthorn, exists as wild populations that inhabit uncultivated uplands of Coruh Valley in the northeastern part of Turkey; the fruit is used to make preserves. We examined genetic diversity in wild-grown Prunus spinosa; 16 individual plants from wild populations of Coruh Valley were sampled and subjected to RAPD (random amplified polymorphic DNA) analysis. We tested 51 random decamer primers; 15 of them gave reproducible polymorphic patterns. These 15 primers produced 226 bands, of which 65% were polymorphic. A UPGMA dendrogram clearly divided the genotypes into four groups; we concluded that RAPD analysis can be used for examining genetic relatedness among blackthorn genotypes.