Depression is one of the most common neuropsychiatric conditions, with a lifetime prevalence approaching 17%. Although a variety of pharmaceutical agents is available for the treatment of depression, psychiatrists find that many patients cannot tolerate the side effects, do not respond adequately, or finally lose their response. On the other hand, many herbs with psychotropic effects have far fewer side effects. They can provide an alternative treatment or be used to enhance the effect of conventional antidepressants. A number of recent preclinical and clinical studies indicate that stigma and petal of Crocus sativus have antidepressant effect. Our objective was to compare the efficacy of petal of C. sativus with fluoxetine in the treatment of depressed outpatients in an 8-week pilot double-blind randomized trial. Forty adult outpatients who met the DSM- IV criteria for major depression based on the structured clinical interview for DSM- IV participated in the trial. Patients have a baseline Hamilton Rating Scale for Depression score of at least 18. In this double-blind and randomized trial, patients were randomly assigned to receive capsule of petal of C. sativus 15 mg bid (morning and evening) (Group 1) and fluoxetine 10 mg bid (morning and evening) (Group 2) for a 8-week study. At the end of trial, petal of C. sativus was found to be effective similar to fluoxetine in the treatment of mild to moderate depression (F=0.03, d.f.=1, P=0.84). In addition, in the both treatments, the remission rate was 25%. There were no significant differences in the two groups in terms of observed side effects. The present study is supportive of other studies which show antidepressant effect of C. sativus.