Corticotropin stimulation tests were used to assess adrenocortical function in 32 patients with septic shock. 13 patients had a poor cortisol response (rise less than 250 nmol/l) to corticotropin, all of whom died. However, there were only 6 deaths among the 19 patients with adequate responses (p less than 0.001). These results suggest that some patients with septic shock may have relative adrenocortical insufficiency.