This study was designed to determine the effects of interferon alpha - 2b and octreotid treatments on some hormonal parameters in rats. Total 36 Wistar - Albino male rates were used as control (n = 12), interferon alpha -2b (n = 12) and octreotide (n = 12) groups. 250.0001U of interferon alpha - 2b was introduced to interferon group rats at intervals of 48 hrs. To the octreotide group rats, 3 times in a day (8 hrs intervals) for 7 days, 10 mg oct-reotide was injected subcutaneously with a insulin ınjector. The levels of TSH, total T4, total T3, testosteron and growth hormone were determined in blood samples of the rats by RIA. Plasma TSH levels of interferon alpha-2b group was found lower than that of control group (P<0.05). However, no significant difference in T3 and T4 levels were determined among control, ocreotid and interferon treated groups. (P<0.05). It was established that in-terferon alpha - 2b and octreotide treated groups have lower testosteron levels than that of control group (P<0.05). Inteıferon alpha 2b group had lower testosteron levels comparing to octreotide treated group (P<0.05). Nevertheless, there was no significant difference in the growth hormone levels of the groups_ The results of the study showed that the treatments of interferon alpha 2b and octreotide can be affect some hormonal parameters in the rats.