This study investigated whether the effectiveness of an error management approach to training negotiation knowledge and skill depended on individual differences in conscientiousness, extraversion, and openness to experience. Participants were randomly assigned to two training programs that incorporated key elements of an error management and behavioral modeling approach to training, and were trained in the complex interpersonal skill of negotiation. At the end of training, declarative knowledge acquisition, procedural knowledge acquisition, declarative knowledge retention, and transfer performance were assessed at different points in time. Results suggested that the effectiveness of the error management training program was dependent on individual levels of conscientiousness and extraversion. For several learning outcomes, the performance of highly conscientious and extraverted individuals was superior in the error management condition, while the performance of less conscientious and introverted individuals was superior in the behavioral modeling condition. The implications of these findings, and suggestions for future research, are discussed.