The purpose of this research study is to expand upon the body of knowledge and research regarding the conditions and processes for effective decision-making in virtual team environments. Specifically, this study sought to demonstrate that teams instructed in consensus produce higher quality decisions and attain the assembly effect (synergy) on complex decision tasks. In addition, teams in virtual communication environments will produce higher quality decisions and attain the assembly effect (synergistic decisions) less often than face-to-face teams on complex decision tasks. Mostly undergraduate students from business courses (N = 358) completed the NASA Survival Exercise complex decision task first individually, then as teams. Subjects were randomly assigned to teams; teams were randomly assigned to one of two decision mode conditions: i) instructed in the consensus decision technique; and ii) not-instructed in the consensus decision technique. Subjects were then randomly assigned to one of three communication mode environments: i) face-to-face; ii) instant messaging; and iii) videoconferencing. A 2 X 3 between-subjects factorial design was used to examine the research questions. The hypotheses compared several mean decision performance measures for three and four-person teams (n = 105) differing in decision mode (consensus instructed vs. not-instructed) and differing in communication mode (face-to-face) or one of two virtual communication environments (instant messaging or videoconferencing). Hypotheses for the decision mode main effect, the communication mode main effect and the interaction effect were not statistically significant. However, the decision performance measure means for communication mode and the interaction between communication mode and the decision mode were in the predicted direction. Future research is needed to clarify the influence of consensus instruction and technology-mediated communication environments on virtual teams.