Concentrations of cortisol in the plasma of harp seal, Phoca groenlandica, pups under three weeks of age are reported to be less than 67 ng/ml (Engelhardt and Ferguson, 1980). Cortisol levels were examined in harbor seal, Phoca vitulina richardsi, pups under four weeks of age. These animals, rescued by the California Marine Mammal Center, suffered from a respiratory distress syndrome and all had cortisol values considerably higher than those reported in harp seal pups. Various possible suggestions for elevated cortisol levels and the role the adrenal cortex may play in the harbor sea! respiratory distress syndrome will be discussed.