The problem of addiction is one of the four global crises. These patients are more vulnerable to mental disorders. This study aimed to examine the risk of suicide in drug dependent patients.In this cross-sectional study, patients who referred for addiction treatment were selected and the control group was chosen among their companions who did not have narcotic drugs dependence. Suicide risk was assessed through California Suicide Risk Assessment Questionnaire. Beck's Depression Inventory questionnaire was used to assess the depression level.The comparison of average education (P < 0.01) and the unemployment rate (P = 0.03) and previous attempted suicide (P = 0.01) between the narcotic drug dependent group and control group showed a statistically significant difference. Suicide risk score (P < 0.01) and depression score (P < 0.01) differences were statistically significant. The average scores of depression score in addicts was significantly associated with their previous attempted suicide (P = 0.01). In the control group, there was a significant association in suicide score and depression score with their previous attempted suicide (P < 0.01). Suicide score were compared based on the depression degree in both groups and statistically significant differences were found (P < 0.01).The suicide risk and depression in drug addicts are more than general population and they are closely related to each other.