Stress is a condition which disturbs physiological and psychological homeostasis mechanism. Depression is a severe psychiatric disorder. Biogenic amine theory of depression illustrate that the low level of brain 5 hydroxy tryptamine (5-HT) and catecholamine leads to depressive symptoms. Immunological challenges can alter the tryptophan (TRP) metabolism, it is clinical indication of depression but stress also shift TRP metabolism. Fluoxetine is more effective anxiolytic drug as compared to others antidepressants. The aim of the current investigation is to examine the effects of fluoxetine administration on tryptophan metabolism and disposition in forced swimming test (FST) in rats. Albino Wistar rats were separated into three groups. Each group had 5 rats. Control animals received vehicle (DMF:Saline, 1:3 v/v) while test group treated with vehicle or fluoxetine (20 mg/kg) (i.p) 3.5 hr prior to FST . Present study shows that holo, total enzyme activity was inhibited when rats subjected to FST and serum total TRP concentration was decreased while liver, brain TRP, 5-HT and 5-HIAA levels were increased in vehicle treated FST rats. Pretreatment with fluoxetine did not reduce immobility however it inhibited holo, total and apo enzyme activity. Pretreatment of fluoxetine also decreased serum total TRP and brain 5HT concentration while increased liver TRP, brain TRP, and 5-HIAA in FST rats when compared with their respective controls. Acute treatment with fluoxetine did not reduced immobility but it decrease brain 5-HT concentration by converting into 5-HIAA in FST rats which shows anxiolytic effect of fluoxetine.