Thrips tabaci is an important pest of onion crops and causes significant yield losses globally. This study aimed at evaluating the efficacy of different insecticides to control onion thrips on onion crops during the years 2021–2022. The experiment was set up and conducted in an open field located in the village of Barilevë, municipality of Prishtina, Kosovo. The experiment design was according to randomized Fisher blocks in three replications. Insecticides were from different groups of chemicals: Mospilan 20 SP (Acetamiprid), Actara 25 WG (Thiametoksan), Talstar 10 EC (Bifenthrin), Karate 2.5 EC, Dimetogal (Dimetoat), Deltarin 2,5 EC (Deltamethrin), and control. The insecticides treatment were in minimal and maximal doses as recommended by the producers. All the insecticides were significantly better than untreated checks at reducing onion thrips numbers after the application of each of the doses. Even though there were no significant differences between the insecticides used in terms of reducing the onion thrips population, Karate has shown the highest efficiency in reducing the number of onion thrips, while Talstar showed to be the least efficient. Therefore, we recommend the use of all insecticides at minimal doses to control the pest in onions.