The diamondback moth, Plutella xylostella, is the greatest damaging insect of cabbage plants. Two field experiments were conducted at private farm in El-Kattawia area, Abu-Hammad City, Sharkia Governorate, Egypt to assess the effectiveness of abamectin 1.8 EC against cabbage diamondback moth. Two field experiments were performed at the same farm in different seasons (2019 and 2020).The experiments were conducted in a randomized block design with a plot size of 4 x 5 m with three replications. The concerned treatments were enjoined four times at 14 days intervals beginning from the 30th day after cultivation. The pneumatic Knapsack sprayer was used to spray fluid (600 liters per hectare). Observations on larval population were made before spraying and on 3, 7, 10, and 14 days after spraying from 10 randomly tagged plants in each plot. Four doses of abamectin @ 9, 11,13, and 15 g a.i.ha-1 were assessed against the Plutella xylostella under study. Besides, Cypermethrin 10 EC @ 70 g a.i./ha , endosulfan 35 EC @ 420 g a.i./ha, spinosad 45 SC @ 75 g a.i./ha, and an untreated blank were also included in the field experiment.The findings concluded that treating with abamectin at 15 g a.i./ ha was the highest mean reduction which meaningfully blocked the population of diamondback moth larvae and recorded a mean reduction of 72.5, 70.7, 75.2, and 78.0 percent from untreated check after first, second, third and fourth sprays, respectively. While the results obtained from abamectin at 11 g a.i./ ha were on par with standard check spinosad at 75 g a.i./ha and excelled over cypermethrin and endosulfan. A similar trend was also observed in the second experiment. The yield of cabbage heads also increased significantly at all the doses tested in the two experiments under field conditions as compared to the control plot. The study demonstrates the potentiality of abamectin 1.8 EC as an eco-friendly bioinsecticide against the diamondback moth (Plutella xylostella). The doses of the studied abamectin @ 15, 13, and 11 g a.i.ha-1 were found to be highly effective to control the infestation of diamondback moth in the cabbage plants under the conditions of a semi-arid zone in Egypt.