We tested whether increased caffeine consumption exacerbates stress and disrupts team performance, and we explored whether “tend and befriend” characterizes women's coping. We gave decaffeinated coffees, half of which contained added caffeine, to coffee drinkers in same-sex, same-aged dyads. We measured individual cognitive appraisals, emotional feelings, bodily symptoms, coping, and performance evaluations, together with dyad memory, psychomotor performance, and negotiation skills under higher or lower stressful conditions. Evidence consistent with the first hypothesis was weak, but we found that women performed better than did men on collaborative tasks under stress, provided caffeine had been consumed. The usefulness of multi component, cognitive-relational approaches to studying the effects of caffeine on stress is discussed, together with special implications of the effects for men.