Laboratory experiments were conducted to assess the reproductive success ofSteinernema carpocapsae(Weiser) orHeterorhabditis bacteriophoraPoinar in soilborneSpodoptera exigua(Hübner) previously exposed toBeauveria bassiana(Bals.) Vuill. Treatments ofH. bacteriophoraplusB. bassianaresulted in higher total mortality ofS. exiguain soil than treatments with either nematode alone or fungus alone. ForS. carpocapsaeplusB. bassiana, insect mortality was not significantly different compared withS. carpocapsaealone. In treatments with nematode plus fungus, percentage mortality ofS. exiguafromS. carpocapsaeandH. bacteriophorawas reduced relative to the treatments with nematodes alone. These results suggest that inundative release of entomopathogenic nematodes whereB. bassianaoccurs may result in greater control of soilborne insect pests than application of nematodes alone.