Aim: The aim of the study was to determine the responses of adrenal corticotropic hormone (ACTH), cortisol, thyroid-stimulating hormone (TSH) and prolactin (PRL) levels during community-acquired infections with fever and to compare changes of these hormones to febrile and afebrile episodes. Methods: Plasma levels of ACTH, serum levels of cortisol, TSH and PRL of 60 hospitilized patients were evaluated prospectively. Blood samples from study group were taken 2 times; during pyrexia and one hour after decreasing of fever. Only one blood sample was taken from each control patient and time of blood sampling was same for all of them. Results: 60 hospitalized patients were included to the study. Of these, 29 were study group, 31 were control group. In febrile patients with infection; plasma ACTH levels was higher than the control group (37,35±35,82 pg/mL vs 22,78±28,84 pg/mL) but no statistical significance was found (p=0,101). Serum cortisol levels was higher than the control group (28,88±13,12 ug/dL vs 17,68±7,88 ug/dL) (p<0,001). There were no differences in serum PRL and TSH levels between the two groups. In the study group plasma ACTH and cortisol levels were significantly increased in febrile periods when compared to afebrile periods (32,21±28,51 pg/mL vs 18,93±22,86. pg/mL; p=0,002) and (28,32±12,96 ug/dL vs 23,09±15,05 ug/dL; p=0,024) respectively. In PRL and TSH levels there was no statistically significance. Conclusion: We concluded that plasma ACTH and serum cortisol elevations are common in acute infectious diseases, and they are more sensitive to increasing of body temperature. The two peptides may be involved in central mediation of fever, perhaps limiting the febrile response acting as neuromodulators in central thermoregulatory pathways.