Objectives According to the noticeable prevalence of substance abuse in veterans of Iran-Iraq War in addition to failures of quit programs, we aimed at determining the etiologies of addiction relapse and possible solutions in these people. Methods Between April 2009 and July 2009 all 122 opiate-dependent veterans with at least one relapse who were under detoxification protocols from Psychiatric institutions affiliated to Iranian Foundation of Martyrs and Veterans Affair in Tehran and Isfahan were considered for the study. They were asked to complete a questionnaire regarding their addiction including substance and its method of administration, onset and duration, daily cost, date and number of attempts to detoxification as well as their socioeconomic status. An informed consent was obtained from each patient. Collected data were analyzed using SPSS 18® software. Results 122 patients were enrolled to the study who were all men with mean age 42.9(±4.2) years. Opium and Heroin were being used by 77% and 13.9% of patients, respectively. No significant difference was found between parameters of socioeconomic status and numbers of Relapse. Moreover, neither administration method nor substance of addiction was significantly different from socioeconomic status of the society. Interestingly, rehabilitation period was significantly longer in opium users than in heroin users (14.18 vs. 10.62 months, p=0.002) whereas detoxification attempts were significantly more in heroin users than opium users (4.41 vs. 3.17 times, p=0.000). And last but not least, main etiologies of relapse were found to be war memories flashback and related PTSD (30.7%), mental dependency (23%), pain (20.5%), unplanned leisure time (12.3%) and family pressures (6.6%). Conclusion Main etiologies of detoxification failure were demonstrated to be due to PTSD and mental pressures. Therefore, these factors much be noticed by the government so that proper facilities can be provided. Greater sample sized study may elucidate more reliable and thorough results.