Six neonicotinoid chemicals were evaluated for their bioefficacy against Scirtothrips dorsalis Hood infesting chilli in West Bengal. It was evident that all the treatments of neonicotinoids except dinotefuran 20 SG, performed significantly better than the standard check, acephate 75 SP. Acetamiprid 20 SP emerged to be the most effective treatment recording highest reduction in thrips population (90.31%) and per cent increase in yield (63.48%). The remaining neonicotinoid chemicals provided satisfactory reduction in the thrips population ranging between 75.53 to 85.97% as compared to 77.68% in acephate 75 SP. Acephate 75 SP recorded a mere 14.54 percent increase in yield as compared to 30.83 to 56.55 percent in the remaining neonicotinoids evaluated. Acetamiprid 20 SP was observed to be the safest treatment against important natural enemies in the chilli ecosystem closely followed by thiamethoxam 25 WG and imidaloprid 17.8 SL while acephate 75 SP was the most toxic treatment. Acetamiprid 20 SP registered the highest yield (18.98 tons ha^-1) and CBR (1:89.97) followed by thiamethoxam 25 WG and imidaloprid 17.8 SL whereas the lowest yield (8.11 tons ha^-1) and CBR (1: 1.32) was registered in acephate 75 SP.