Turcicum leaf blight (TLB) caused by the fungus Exserohilum turcicum is a serious threat toproduction of maize and sorghum, since it damages photosynthetic leaves. Growth and development of E.turcicum pathogen is influenced by factors such as light, temperature, dew period, plant age and inoculumsconcentration. Tharaka Nithi County in Eastern Kenya where sorghum is actively grown has heterogenous climatic and edaphic conditions. It is currently unclear if variations in temperature and media type may influence growth, development and virulence of Exserohilum turcicum. Thus, this study was carried out to investigate the effect of media type and different temperature variations on the growth and development of mycelia of E. turcicum isolates from Tharaka Nithi County in Kenya. Results showed that the effect of temperature was significantly differences for development of E. turcicum (Pr < 0.05) mycelia. Media type had significant effect on growth of E. turcicum isolates (p<0.05). Corn meal agar with mean of 4.233 cm was the best growth media followed by Malt extract agar at 3.3200 cm, while the most preferential (p<0.05) temperature for mycelia growth was 30 oC. The study recommends in cooperation of wider environmental factors in future studies involving TLB pathogen from Tharaka Nithi County.