A new unified nomenclature system of downy mildew races was intro duced in 2000 (Tourvieille et al., 2000). The present study has the aim to determine the distribution and race composition of sunflower downy mildew in Bulgaria according to this new nomenclature. During 2000-2003, 57 samples were collected from infected plants and their race affiliation was determined. According to the results obtained, three downy mildew races were isolated during this period: races 100, 300 and 700. Race 100 had the most limited distribution, 3.5% of the downy mildew population. It was detected only during the first year of the investigation. Race 300 was isolated during all years of study. Its percent in the pathogen population was 36.8% averaged for the period. It was distributed mainly in the southeastern, northwestern and central parts of Bulgaria. Race 700 had the widest distribution during the period of investigation. It was isolated from 34 out of a total of 57 samples analyzed, which was 59.7%. Its area of distribution was mainly in northeastern Bulgaria.