This study examined the variation in the diurnal profile of cortisol, with an emphasis on the cortisol awakening response (CAR), in relation to mood states and performance during a professional swimming contest. Eleven athletes were examined during 2 consecutive days of competition and during a recreated event 2 weeks later that was matched to the time of the day and day of the week of the competition. On each day, salivary cortisol was determined upon awakening (07:00 hours); 30 and 60 minutes post-awakening; immediately before warming up for competition (16:00 hours); and 5 minutes (18:20 hours), 20 minutes (18:40 hours), and 40 minutes (19:00 hours) after competition. Psychometric instruments included the Profile of Mood States and self-reports of performance. Cortisol awakening responses did not differ between days of competition and control and were not related to performance on any day. However, a difference was observed in the concentration of cortisol before and after the contest between the competition and control days. Higher levels of cortisol before competition were associated with feelings of tension, anxiety, and hostility. The perceived demands of the day ahead might not produce the same magnitude of variation in the CAR in well-trained men. Explanations for this probably include better coping mechanisms and responses to the phase and time of competition.