The low cassava production recorded in farmers’ fields in Kiyaka suggests attacks caused by Helopeltis sp. as well as certain marginal cultural practices that may be responsible for the extent of the damage caused by this insect. In this context, a trial was conducted at Kiyaka- Plateau to determine the impact of damage caused by Helopeltis sp. on cassava tuberous root yield. The study involved five improved cassava varieties currently being disseminated throughout the province. The objective of this study was to identify the types of damage and assess their impact on yield in order to establish pest management options. The experiment was carried out using a splitplot design with three replications and five treatments corresponding to the five cassava varieties. The performance of the five tested varieties with respect to damage caused by. Helopeltis sp. was evaluated based on the percentage of attacked plants (incidence) and the degree of damage for each variety (severity). The pest population observed was determined by systematically counting the number of individuals recorded.