Morphological characters and morphometric measurements are used for diagnosis and identification of nematodes. In some cases, reliable results can not be achieved by classic methods. Therefore, molecular markers have been applied to nematode identification. Molecular markers are methods based on DNA. In this article, information regarding to the most common molecular marker techniques including Restriction Fragment Length Polymorphism (RFLP), Amplified Fragment Length Polymorphism (AFLP), Microsatellites (SSR, STR, ISSR), Random Amplified Polymorphic DNA (RADP), Single Nucleotide Polymorphism (SNP) and DNA Sequence Analysis (mtDNA and rDNA) was given and the studies done by using these methods were reviewed.