Introduction: The purpose of this study was to determine changes in salivary immunoglobulin A concentrations (S-IgA) & cortisol levels and any relationship between them, in adults after eight weeks of moderately intense exercise in the morning. Material and Methods: Thirty, healthy, adult men (aged 30-50 years) having a sedentary lifestyles, were randomly selected and assigned to either the control or the exercise group their exercise program consisted of three sessions a week, for eight weeks. Each subject performed exercise at 06:00 a.m at 75% of maximum heart rate during the study, while controls continued their normal life style. Changes in fasting S-IgA concentrations and cortisol serum levels were monitored at the beginning and end of exercise at (0900) a.m following every session. Analysis of data was performed, using t-student test for comparing means of pre and post test. Pearsons correlation was used to determine any relationship between S-IgA concentration with cortisol concentration. The level of significance was chosen at P≤0/05. Results: Results indicated significant changes in S-IgA concentrations in the pre and post exercise evaluations for the experimental group, while these remained unchanged in the control group. No significant differences were observed in serum cortisol levels, between experimental and control groups, without any relationship with salivary cortisol. Conclusion: Regular moderate exercise in the morning seems to enhance some factors of mucosal immune function in adults, which, in turn may contribute a decrease risk of infection.