Motives were assessed from the TAT, stress and illness from self-report inventories, and immune function from concentrations of immunoglobulin A in saliva (S-IgA). Those high in n Power and in reported stress showed the highest levels of reported illness and the lowest concentrations of S-IgA, significantly different from those high in n Power and low in stress, or from all other subjects, but not from those simply high in stress. Although the stress-illness association may be due to a response bias to complain about everything, the motive/stress and lowered immune-function connection cannot be attributed to response bias. Among prisoners the effect of motive type is less and the effect of stress is greater than among college students perhaps because stress in prison is stronger. As expected, high concentrations of S-IgA were associated with reports of fewer upper respiratory infections supporting the hypothesis that some motive/stress and illness connections may be mediated by impaired immune-functions. (Publisher abstract)