The use of microsatellite analysis in a forensic procedure for establishing infringement on plant breeders¿ rights in vegetatively propagated crops was evaluated. A reference collection of 45 seedless grape varieties was chosen as reference collection. Matching probabilities of grape microsatellite genotypes were calculated under the assumption of independent breeding programs. After testing for independence of alleles within and between loci a set of 5 microsatellite loci was chosen as basis for the calculation of matching probabilities. Even the highest matching probabilities were so low that a forensic procedure using microsatellites seems to provide a sound basis for assessing infringements on plant breeders¿ rights for the case of grape.