Cassava mosaic disease caused by begomoviruses of Geminiviridae family is one of the major constraints for the Cassava production in many Cassava growing states of India. The disease is known to be transmitted by whiteflies Bemisia tabaci and spread though the infected Cassava planting material. In India the Cassava mosaic disease (CMD) is caused by both Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV). However, Sri Lankan cassava mosaic virus was the most predominant virus species in the study area. To assess the severity of CMD, a survey was conducted during 2021-2022 in different blocks of the Namakkal district, Tamil Nadu state. The incidence was ranging from 34-95 percent, highest 95 % was recorded in Venandur and lowest 34 % was recorded in Elachipalayam block. The disease prevalence was ranging from 36-85 percent, highest 85 % was recorded in in Paramathi and lowest 36 percent recorded in the Elachipalayam block respectively. Variety Sree Padmanabha was found to be resistant for the Cassava mosaic virus in a trial conducted in a farmers’ field in Venandur block. Growing of CMD resistant varieties and use of disease-free Cassava planting material are the most important and economically feasible practices in the management of the Cassava mosaic Disease.