The purpose of the present study was to assess the effect of a time limited cognitive-behavioral stress management program (CBSM) on mood state and serum cortisol among men and women rowers (N = 34) undergoing a period of heavy exercise training. After controlling for life-event stress (LES), CBSM was hypothesized to reduce negative mood state and cortisol among rowers during a period of heavy training; mood and cortisol changes over the intervention period were hypothesized to be positively correlated. LES was positively associated with negative affect at study entry. After covariance for LES, rowing athletes randomly assigned to the CBSM group experienced significant reductions in depressed mood, fatigue, and cortisol when compared to those randomized to a control group. Decreases in negative affect and fatigue were also significantly associated with cortisol decrease. These results suggest that CBSM may exert a positive effect on athletes' adaptation to heavy exercise training.