The present study concurrently measured psychological distress (state anxiety, depression, confusion, and intrusive thoughts), neuroendocrine (plasma cortisol concentrations), and immunologic [lymphocyte proliferative responses to phytohemagglutinin (PHA) and pokeweed mitogen (PWM)] changes in the 5-week periods preceding and following serostatus notification among asymptomatic Human Immunodeficiency Virus-type 1 (HIV-1) seropositive and seronegative gay men. Seropositives, as opposed to seronegatives, showed a disparity in predicted relationship among distress, cortisol, and immunologic measures across the prenotification to postnotification period. Individual difference analyses suggested that among seropositives, in contrast to seronegatives, plasma cortisol concentrations were negatively correlated with psychological distress and positively correlated with responses to PHA (assessed at study entry and after serostatus notification). This pattern in seropositives could not be explained by differences in prenotification perceived risk of infectivity, extraneous environmental stressors, or CD4 cell counts within the seropositive group.