Introduction: Mental disorders play an important role in suicide occurrenceso that more than 90 percent of suicide victims are suffering from a mental disorder at the time of death. The present study aimed to det-ermine the epidemiological aspects of suicide due tomentaldisordersin Ilam pro-vince. Material &Methods: Through a cross-sec-tional study, all records of suicide events either completed or attempts (n=5188) were investigated in Ilam province during 1993 to 2009. A Chi-square and multiple logistic regressions analysis was adopted to estim-ate the role of risk factors associated with suicide events due to mental disorders. Findings: In overall, 27.5% of suicides oc-curred due to mental disorders. The highest frequency of suicides due to mental dis-orders belonged to males (29.3%), indi-viduals with and over 30 years old (33.2%), attempted suicide (28.3%), the year 1996(44%) and the decade of 1990s (30.3%). The risk of suicide due to mental disorders was estimated to be (OR=0.85, CI=0.74-0.97) for females, (OR=2.42, CI= 1.79-3.26) for the year 1996, (OR=0.79, CI= 0.67-0.93) for completed suicide and (OR=0.82, 0.66-1.01) for the age group of 25 to 29 years old. Discussion &Conclusion: It is required to train people at risk including attempted su-icides among males