Background: The incidence of suicide is higher in individuals with post-traumatic stress disorder (PTSD) than the general population. This prevalence rate is related to many factors including drug dependence. This study was conducted in people wounded during the Iran-Iraq war with PTSD, in order to compare the risk of suicide in those with and without drug and nicotine dependence.Methods: This cross-sectional study, conducted in 2007–2008, comprised 104 male individuals who had participated in the Iran-Iraq war and had a current diagnosis of PTSD. They had been referred to a psychiatry hospital and the psychiatrists' offices in Kerman, Iran. Three questionnaires were used including Davidson Trauma Scale, California Risk Estimator for Suicide and the Fagerstrom Test for Nicotine Dependence to assess the severity of PTSD, the risk of suicide, and nicotine dependence, respectively. Data were analyzed by descriptive and analytical statistics using Chi square, regression, analysis of variance (ANOVA), student-t and correlation tests.Findings: The sseverity of PTSD was significantly different in individuals with low to moderate dependence on cigarette smoking than in those with heavy dependence on smoking (P = 0.002). However, the corresponding figures were not significantly different in individuals with and without substance abuse. Although the risk of suicide had no significant difference among individuals with low to moderate dependence on cigarettes compared to those with high nicotine dependence, it was higher in subjects with substance abuse than in those without it (P = 0.0001).Conclusion: Our findings suggest that dependence on cigarettes may not play a role in increasing the risk of suicide, whereas the dependence on opium and its derivatives may increase this risk. Therefore, prevention and treatment of drug abuse may be effective on the incidence of suicide in patients with war injuries and PTSD.Keywords: Suicide, Drug dependency, Post-traumatic stress disorder, Iran.