Illegal logging is a major problem in many European countries. Recent progress in molecular biology, however, has significantly improved the ability to accurately identify wood material. In this paper, the first application of microsatellite DNA markers is described in a case of illegal logging of European ash wood in Polish State Forests. The genetic fingerprints of seized ash wood samples were determined using six nuclear and four chloroplast microsatellite loci, characterized by sufficient stringency in forensic analyses. By comparing the DNA profiles obtained, the origin of one sample of ash wood used as evidence material was confirmed, from among three samples serving as reference material with 99.99999% of probability. This work demonstrates how DNA authenticity testing can serve as an important technical tool in monitoring the legality of the suspected ash timber and confirms the utility of these techniques in detecting illegally logged timber in general.