As part of ecological monitoring, the managers of the Nazinga Classified Forest and Game Ranch, the Management Unit, regularly carry out measurements on the carcasses of animals killed during sport hunting during the wildlife exploitation campaign. The measurements taken from 2009 to 2018 on the defassa waterbuck carcasses were examined in order to assess the quality of the hunting trophies and its impact on the dynamics of the species population. Data collected on the measurements of the trophies at the ranch slaughterhouse and the results of the various wildlife foot inventories served as a basis for the analyses. The results of the analyses show that the defassa waterbucks killed are old males with trophies that meet the standards, although their size decreases from year to year. This rejuvenation of the population creates a flattening of the age pyramid. Successful sport hunting combined with other factors such as habitat degradation and poaching could lead to a decline in the population size of the defassa waterbuck. Keywords : Sport hunting ; Trophies ; Nazinga ; Defassa waterbuck ; Rejuvenation