Aims: This study focused on the assessment and identification of key insect pests on sweet oranges (Citrus sinensis) plantation in Tony farm of Dire Dawa town. It was also explain the abundance of key pests and effective controlling methods. Methodology and Results: The farm lands of sweet oranges stratified in to nursery stage and adult stage by using stratification method technique. Then random sampling method of data collection was carried out in both strata. By this method direct observations were taken place and the data collected from this area were analyzed. The larvae and adult stages of key insect pests of sweet oranges were identified by using the dissecting microscope. Citrus leaf miners, leaf dogs and cottony cushion scale are key insect pests of sweet oranges in this area. From these citrus leaf miners are highly dominant where as orange dog is less in abundance. Conclusions: Citrus sinensis plants in Tony farm are highly damaged by these key insect pests particularly nursery stages of plants are devastated.