Bipolar disorder type I is one of the most disturbing psychiatric syndromes .It is basically treated by stablizing mood medicienes , psycho- social intervention and, in accute cases ,Electro convulsive therapy . As resources with Omega 3 have been considered effective in treatment of many diseases as well as mental disorders, we decided to study effect of Omega 3, compared to Feluvoxamine, on the treatment of depression in bipolar patients referring to. psychiatric clinic Materials and Methods:The present study which is a clinical trial , carried out on 80 patients selected using double blind randomization in two groups :case and cotrol .The case group Took Feluvoxamine and Omega3 tablets and the control group received only Feluvoxamine . All the subjects were given Hamilton Rating Scale as well as psychiatric clinical interview from the start of the study and after the second ,fourth eighth and twelfth weeks . The data were analyzed after they were collected . Results:The results of the study showed that the mean of the marks in Hamilton Depression Scale in both groups under study in the start of the study and in 2nd, 4th, 8th and 12th weeks was decreased significantly and the patients ‘performances were improved . The statestical Repeated Measures showed a significant difference in mean of depression marks in both groups before the treatment program and in weeks 2 , 4 , 8 and 12 . Conclusion :Considering research findings related to the effect of Omega3 and its harmlessness , it is suggested that Omega3 can be prescribed with other anti depressive medicines