We examine the factors affecting the willingness of German farmers to adopt genetically modified (GM) oilseed rape after the pending commercial release of GM varieties. The analysis is based mainly on a web-based Discrete Choice Experiment with 217 oilseed rape growers in Germany. The determinants of adoption were estimated with the use of a multinomial probit model. Results indicate a significant impact of economic determinants on the adoption willingness: the difference in gross margins between GM and conventional rape, the probability and level of liability for damage caused by cross-pollination, and the length of the waiting period before a farmer can return to conventional rape are all highly significant. Among the farm characteristics, farm size increases the willingness to adopt, while the share of oilseed rape grown has a negative impact. Two social factors decrease the willingness to adopt: negative attitude of neighbouring farmers towards GM oilseed rape and whether at least one of the farmer’s children is younger than 16. Personal characteristics such as degree of innovativeness and the level of education increase the willingness to grow GM rape, while the existence (or otherwise) of a successor, farmer’s age, and his or her degree of cooperativeness are not significant. For a successful market launch of GM oilseed rape, our findings suggest the need to identify strategies for farmers to minimize cross-pollination. A successful market launch should thus not only rely on the availability of profitable GM varieties; it should rather be complemented by a communication offensive to influence farmers’ attitude towards genetic engineering, as well as the provision of technical advice as to how cross pollination can be kept to a minimum.