Most regulatory authorities require that developers of genetically engineered insect-resistant crops evaluate the potential for these crops to have adverse impacts on organisms not intended to be controlled by the trait, referred to as non-target organisms (NTOs). Conducting NTO testing poses both conceptual and logistical challenges for researchers, and the challenges are likely to increase as these crops are considered for commercial planting in a growing number of new geographic locations. The key is to select test species that best represent the valued NTOs in the area in which the GE crop is going to be introduced, and there are many variables to be considered: surrogates must be either field collected and reared, or purchased, as large, uniform populations; they must perform well on an artificial diet and be amenable to manipulation under laboratory conditions; and validated test protocols must be available. But the most important goal, from the standpoint of regulatory decision making, is that the data derived from surrogates should accurately predict any adverse impacts likely to be observed from the use of the crop in the agricultural context. These issues were the subject of the conference “Surrogate Species Selection for Assessing Potential Adverse Environmental Impacts of Genetically Engineered Plants on Non-Target Organisms” convened by the Center for Environmental Risk Assessment (CERA), ILSI Research Foundation, June 26-28, 2012. This report summarizes the proceedings of the conference, including the presentations, case studies, breakout and plenary discussions, and the points of consensus agreed to by the participants.