Investigators in the field of stress concur that exposure to intense stressors impairs individuals' decision making. A considerable ambiguity exists, however, with respect to the factors and processes that mediate this effect. The present study tested the proposition that deficient decision making under stress is due, to a significant extent, to individuals' failure to adequately fulfill a most elementary requirement of the decision-making process, i.e., the systematic consideration of all relevant decision alternatives. Participants in this experiment were required to solve decision problems while under stress. Their performance was compared to that of an unstressed control group. Stress was found to induce a tendency to offer solutions before all decision alternatives had been considered and to scan such alternatives in a nonsystematic fashion. In addition, patterns of alternatives-scanning were found to be correlated with the quality of solutions to decision problems.