Business organizations emphasize the importance of teamwork and collaboration within work groups more than ever before. Unfortunately, group interaction is not always positive. Very little research has been conducted to investigate the behavior and judgments of group members who are belong to group in which one of the members is deceptive. This study is one of the first attempts to look at this phenomenon, from both the deceiver and receiver sides. Groups of three student subjects engaged in a group negotiation task, with one of the group members randomly assigned the role of deceiver. Groups varied by the availability of computer-supported communication for discussion purposes, their physical proximity with one another, and the number of group members who were warned about the possibility of deception. Results indicated that individuals lied more when using computers to communicate with others and when both of their group partners had been warned. Group members were not proficient at detecting lies in any of the conditions. Implications of these findings and their potential implications for research and practice are discussed.