The study was conducted at the Research Field of Entomology Department, Sylhet Agricultural University (SAU) campus and farmer’s field at Sreemangal, Moulvibazar during October 2017 to April 2018 to find out the effectiveness of net barrier in protecting major insect and mite pests of bell pepper. Four treatments viz., plot with coarse net (40-mesh mosquito net) + polyethylene (T₁), plot with fine net (120-mesh nylon net) + polyethylene (T₂), plot with polyethylene (T₃) and control plot (T₄) were used. The experiments were laid out in a Randomized Complete Block Design with five replications. In two sites, chili aphid (Aphis gossypii Glov.), jassid (Amrasca biguttula Ishida), common cutworm (Spodoptera litura Fab.) and white mite (Tetranychus sp.) were found as the major pests. Irrespective study sites, coarse net and fine net reduced 73 to 80% chili aphid, 51 to 74% jassid and 71 to 81% white mite. The treatments had no impact on reducing common cutworm. In both sites, highest fruit yields were obtained from fine net and polyethylene plot in SAU (12.74 t ha^-1) and also in Sreemangal (10.48 t ha^-1). The fine net plot gave higher Marginal Benefit Cost Ratio (MBCR) in SAU campus (MBCR = 7.56 : 1) and Sreemangal (MBCR = 4.9 : 1). The results indicated that fine net use in bell pepper plot is effective in controlling insect and mite pests, producing higher fruit yield and profits.