Spot form net blotch (SFNB) caused by Pyrenophora teres f. maculata is a major foliar disease of barley (Hordeum vulgare L.) worldwide. SFNB epidemics have recently been observed in major barley producing countries, suggesting that the local barley cultivars are not resistant and that virulence of the pathogen populations may have changed. Here we attempt to identify sources of resistance effective against diverse isolates of the SFNB pathogen. A total of 2062 world barley core collection accessions were phenotyped using isolates of this pathogen collected in the United States (FGO), Australia (SG1), New Zealand (NZKF2), and Denmark (DEN 2.6). Isolate-specific susceptibility was identified in several of the barley accessions tested, indicating variability in both pathogen virulence and host resistance/susceptibility. Collectively, only 15 barley accessions were resistant across all isolates tested. Future research will involve the characterization of host resistance, pathogen virulence, and the host-pathogen interaction associated with SFNB of barley.