Helicoverpa armigera Hübner and Spodoptera litura Fabricius (Lepidoptera: Noctuidae) are destructive pests of agricultural and horticultural crops. Excessive use of synthetic chemicals has created harmful impacts on non-target organisms and environment. This study was aimed to assess the insecticidal potential of acetone extracts of 40 indigenous plant species of Soon valley (Khushab, Punjab, Pakistan) against the 3^rd instar larvae of H. armigera and S. litura using leaf-dip bioassay method. Results revealed that maximum mortality of H. armigera larvae was caused by the extracts of Dodonaea viscosa L. (88%), Olea ferruginea Wall. ex Aitch. (69%), Mentha longifolia (L.) Huds. (57%) and Salvia officinalis L. (52.22%), while the extracts of S. officinalis, D. viscosa, O. ferruginea, Sonchus asper (L.) Hill and Nerium indicum Mill. caused significant mortality (i.e. 70 to 90%) of S. litura larvae and exhibited minimum LC₅₀ and LT₅₀ values. These results propose the potential efficiency of indigenous flora against lepidopterous pests and there is a need of further biochemical characterization of these plant extracts.