The African Mosaic of the Cassava is a disease caused by a geminivirus transmitted by the white fly (Bemisia tabaci) in the intertropical zone. This virus contributes to significant drops of the output of the cassava in several African countries, of which the Democratic republic of Congo, where the reduction in the production would be currently allotted to him. For better appreciating the importance of its effects, a study was conducted on fields of cassava to Kindu and its hinterlands in the province of Maniema as a Democratic republic of Congo of 2017-2018. Parameters related to the disease (the incidence, the foliar rate of attacks, the index of gravity of the symptoms and the loss of output) were studied. The study carried out with Kindu showed an average incidence of the disease of 72.26% and one average rate of foliar attack of 75.41%. For the other sites/localities retained the incidences of the disease varied from 91.7% (Mikonde Pk5); 86.6% (Kampala Pk 11); 83.28% (Katako Pk7); 74.62% (Shenge Pk4); 73.38% (Lukungu Pk7) with 38.04% (Lwama Pk7), whereas the rate of foliar attack of the sick seedlings by sites varied from 85.48% to 53% is an average of 72%. In addition, 74.6% of the seedlings studied expressed the disease. Sick seedlings have IGS (Index of Gravity of the Symptoms) worrying (2 to 5), likely cause a drop in the production in the studied zones. The economic impact of the African mosaic resulted in a loss of output at the level of the tubers reducing to a significant degree the efforts of the country farmers. The results got in this study show a relatively worrying situation clearly, deserving a constant intervention. The characterization of the virus, the agronomic research and the creation of the new varieties of cassava tolerant and/or resistant to the African mosaic would prove to be essential.