Net blotch, caused by Pyrenophora teres, is one of the most economically important diseases of barley worldwide. Here, we used a barley doubled-haploid population derived from the lines SM89010 and Q21861 to identify major quantitative trait loci (QTLs) associated with seedling resistance to P. teres f. teres (net-type net blotch (NTNB)) and P. teres f. maculata (spot-type net blotch (STNB)). A map consisting of simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers was used to identify chromosome locations of resistance loci. Major QTLs for NTNB and STNB resistance were located on chromosomes 6H and 4H, respectively. The 6H locus (NTNB) accounted for as much as 89% of the disease variation, whereas the 4H locus (STNB resistance) accounted for 64%. The markers closely linked to the resistance gene loci will be useful for marker-assisted selection.