Dopamine and noradrenaline (NA) are involved in generation of long term potentiation (LTP) which play critical role in learning and memory processes. It is known that the pineal hormone melatonin inhibits LTP in hippocampal neurones involving different mechanisms. Gastric hormone ghrelin is also suggested to involve in enhancement of hippocampal memory processes, but the involved mechanism of this effect is not clear yet. The electrophysiological studies involving LTP are in vitro nature and there is no data on the possible effects of melatonin and ghrelin on NA release and thereby in this process. The purpose of this study was to assess the effects of exogenous melatonin and ghrelin on catecholamine levels in the rat hippocampus. Male Wistar rats (280-300 g) were anaesthetized by administering intraperitoneally choral hydrate (500 mg/kg) before being placed on a stereotaxic frame. Melatonin (n=7) and ghrelin (n=7) were intracerebroventricularly (icv) administered at dose of 1 μg/5μL separately. The animals in the control group received artificial cerebrospinal fluid (icv, n=7) and vehicle of melatonin was administered to the vehicle group (icv, n=7). Following 20 minutes of injections, all animals were sacrificed by decapitation and brains were promptly removed. Left hippocampus tissues were obtained by guidance of rat sterotaxic atlas. The whole hippocampus tissues were homogenised for catecholamine analysis. NA, dihydroxyphenylglycol (noradrenaline metabolite), dopamine and dihydroxyphenylacetic acid (dopamine metabolite) content of samples were analysed in high performance liquid chromatography with electrochemical detector. Mann Whitney-U test was used for statistical evaluation. Melatonin group had significantly lower NA level (33.61±0.72 pg/wet tissue) than the vehicle group (6.97±0.77 pg/wet tissue, p<0.01). Whereas NA level in ghrelin group (10.92±1.05 pg/wet tissue) was significantly higher in ghrelin group compared to control group (6.75±1.48 pg/wet tissue, p<0.05). Dihydroxyphenylacetic level in melatonin group was significantly lower compared to vehicle group (P<0.05). There were no significant differences between the levels of both dopamine and dihydroxyphenylglycol in any groups. The results of this study demonstrate that melatonin has decreasing effect on NA concentration, whereas ghrelin has elevating effect on NA level in the hippocampus. These results may ensure additional evidence for the tested catecholamine on memory, evidenced from electrophysiological studies of these hormones on hippocampal neurons.