Technical Abstract: The southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae), a major pest worldwide, is effectively controlled with egg parasitoids and egg production is an important component of this strategy. Therefore, a laboratory bioassay was developed for testing its oviposition preference toward chemicals extracted from soybean pods and leaves. In this bioassay, an artificial substrate (cheesecloth) was stretched over a wooden ring (embroidery hoops), treated with plant extracts or chromatographic fractions, and then exposed to adult stink bugs to assess oviposition preference. To obtain samples of chemicals for bioassay testing, freeze-dried soybean leaves and pods were extracted, first with hexane, then with methanol, and finally with water. The organic solvent extracts were then fractionated by liquid chromatography, first on a C18 reverse phase column, then on a normal phase silica column, and finally by thin layer chromatography (TLC) on silica gel. The methanol extract of pods showed the greatest bioassay activity. The most active reverse phase fraction derived from this extract was that eluted with 20% methanol in water. After subjecting this fraction to chromatography on silica, the greatest activity occurred in the fraction eluted with 60% methanol in methylene chloride. Further fractionation of this material by TLC gave no single fraction with demonstrated activity, but the recombined fractions were again active, indicating that multiple components may be involved in eliciting oviposition. Hairs (long and short trichoidea) present in the female genitalia might be involved in chemical and/or mechanical recognition of oviposition stimulants.