Reserpine (Res)-induced depletion of monoamines and altered neurotransmission and produces oxidative stress. Tryptophan (TRP) regulated the serotonin neurotransmission. Because systemically injected Res induced behavioral deficits and oxidative stress, while, dietary components prevented these adverse effects, we used TRP a pharmacological tool to prevent Res- induced changes in behavior, memory impairments, oxidative stress and regulation of serotonin neurotransmission in rats. Anxiolytic, antidepressant, cognitive functions, lipid peroxidation, antioxidant enzymes serotonin metabolism were studied in Res and vehicle treated animals following administration of 50 and 100 mg/ml/kg of tryptophan. Following administration of TRP [50 and 100mg/ml/kg], Res induced anxiety-and/or depression like behaviors normalized. Res-induced impaired cognitive function and increased acetylcholinesterase activity also improved following administration of TRP at both doses. Res induced increased brains' malondialdehyde (MDA) and decreased antioxidant enzymes activity also normalized by TRP. Res-induced decreased 5-HT metabolism also regulated by administration of TRP at both doses. In conclusion it can be recommended that administration/supplementation of TRP in daily life can aid in battling the anxiety, depression, modulating serotonergic activity and oxidative stress. Study also exhibits the anti-acetylcholinesterase role of TRP which may be possible reason for improved cognition following stress situation.