The European mink Mustela lutreola is the focus of extensive conservation programmes whereas the American mink M. vison is exotic in Europe and a possible cause of European mink decline. Since both species, together with the European polecat M. putorius have similar hair and produce similar faeces, molecular techniques are essential for reliable species identification when disturbance is not appropriate. In this report a simple, cheap and reliable molecular method for the genetic distinction of mink is provided based on the amplification of the microsatellite locus Mel08 that results in a longer PCR product (436 bp) in American mink than in other mustelid species, such as the European mink (221 bp) and the European polecat (221 bp). Sequencing these PCR products revealed, in the microsatellite-flanking region of American mink, a CAN-SINE insertion of 213 bp that was absent in 22 species of the Canoidea superfamily tested. When the Mel08 PCR product is cut with restriction enzyme AciI and then run in an agarose gel, the restriction pattern observed is different in the three Mustela spp. The method was successfully tested with DNA amplified from a large sample of hair roots, thus making it suitable for non-invasive sampling.