Rice false smut (RFS) is an important rice disease that is caused by the pathogen Ustilaginoidea virens. In this study, we developed a real-time polymerase chain reaction (PCR) assay to detect U. virens and to estimate the level of disease. The genomic DNAs of U. virens and rice were extracted together from the rice samples. Real-time PCR assays were performed and compared to conventional nested-PCR assays. The real-time PCR assay presented a consistent linearity of the standard curve (R2 = 0.9999).