Macrophomina phaseolina (Tassi) Goid. incitant of dry root rot disease in mungbean is the most devastating disease in all the mungbean growing districts of Rajasthan particularly in Bikaner, Jaipur, Bhilwara, Bharatpur, Sri Ganganagar, Jodhpur, Kota and Udaipur. Ten isolates of Macrophomina phaseolina tested for their pathogenic nature, using susceptible RMG-62 variety of mungbean were found virulent in sterilized as well as unsterilized soil. The dry root rot incidence (%) in sterilized soil and unsterilized soil varied from 33.33 to 100 and 26.67 to 83.33, respectively. Isolate Bikaner was most virulent followed by Churu, Hisar, Sri Ganganagar, Junagarh-6486, IARI-5156, Sawaimadhopur, Delhi, Jalana-5156 and Narnaul. Bikaner isolate showed 83.33 per cent disease incidence in unsterilized soil which was less than sterilized soil i.e 100 per cent. In general the mortality of plant in unsterilized soil was reduced over sterilized soil.