Experiments were conducted at the Biological Control Laboratory of the Economic Entomology and Agricultural Zoology Department, Faculty of Agriculture, Menoufia University, Shebin Elkom, Egypt to determine the productivity and effect of entomopathogenic nematodes, Steinernema carpocapsae and Heterorhabditis bacteriophora on some instar larvae of greater wax moth, Galleria mellonella, cotton leafworm, Spodoptera littoralis and black cutworm, Agrotis ipsilon under laboratory conditions. As for G. mellonella larvae the grand mean average revealed that the highest mortality was recorded with the concentration of 1600 IJs (68.8%), while the lowest mortality percentages was registered with the concentration of 50 IJs (33.0%) of S. carpocapsae, and the highest mortality was recorded with 1600 IJs (94.9%), while the lowest mortality was registered with 50 IJs (58.8%) of H. bacteriophora. As for S. littoralis larvae, the highest mortality was recorded with the concentration of 1600 IJs (67.7%), while the lowest was registered with the concentration of 50 IJs (33.0%) for S. carpocapsae , while the highest mortality was recorded with 1600 IJs (95.6%) , and lowest was registered with the concentration of 50 IJs (58.8%) for H. bacteriophora. As for Agrotis ipsilon larvae, the highest mortality was recorded with the concentration of 1600 IJs (63.8%), and the lowest mortality percentages was registered with the concentration of 50 IJs (15.4%) for S. carpocapsae, while the highest mortality percentages was recorded with the concentration of 1600 IJs (77.8%) , and the lowest mortality was registered with the concentration of 50 IJs (43.02%) for H. bacteriophora. It could be concluded that the use of entomopathogenic nematodes, Heterorhabditis bacteriophora and Steinernema carpocapsae in the control of lepidopteran larvae i.e., the greater wax moth, Galleria mellonella, cotton leafworm, Spodoptera littoralis and black cutworm, Agrotis ipsilon registered good results, but it needs more studies.