The necrotrophic fungal pathogen Pyrenophora teres f. teres causes the foliar disease net form net blotch (NFNB) on barley (Hordeum vulgare). To investigate the genetics of virulence in the barley- P. teres f. teres pathosystem, we used 118 progeny derived from a cross between the isolates 15A and 6A. The barley lines, chosen based on their different reactions to 15A and 6A, were evaluated for NFNB caused by the 15A × 6A progeny. Genetic maps generated with SSR and AFLP markers in the fungal population were scanned for quantitative trait loci (QTL) associated with virulence in P. teres f. teres. Two QTL were identified in Rika, two in Kombar and PI356715 had a single unique QTL. Therefore, a total of five virulence loci were identified in this pathogen population based on inoculation on three different barley lines.