ABSTRACT Sugarcane is infected by different types of Diseases which make sugarcane production in Nigeria and all other sugarcane growing countries of the world face a great challenge. However, the use of tolerant variety and resistant variety remains the most effective and economical means of controlling these diseases. Therefore, this study was carried out at the Unilorin Sugar Research Institute Germplasm, during the 2010-2011 cropping season under field condition to measure the incidence and severity of sugarcane smut disease in Osin local sugarcane variety. The Osin local sugarcane was observed for smut incidence and severity level as well as their growth parameters. Data collected include: number of total plant and infected plant under observation, Stalk length of diseased and healthy plants per row, length of healthy and diseased leaves per sample plant [were subjected to Analysis of Variance (ANOVA)]. It was concluded from the results of data analysis, that Osin local sugarcane was susceptible to sugarcane smut infection. The research also shows that sugarcane smut infection can reduce to some extent, the growth of infected plants especially the height, furthermore reducing the mill able cane.