Background: With regard to the perceptible population, cultural, social and environmental changes in the aftermath of the earthquake in Bam City, this study was conducted to pinpoint substance misuse patterns and to figure out the probable relationship between substance misuse and blood types of the addicts referred to Substance rehabilitation Clinics from 2006 to 2007 in Bam City. Methods: In this case-control study, the sample size includes volunteering and self-introduced addicts and also a random selection of 360 healthy clients referred to the Blood Transfusion Organization as the control group. Both groups' data were analyzed using descriptive statistics and Chi square and the odds ratio was estimated too. Findings: Three-hundred ninety nine individuals from nearly 3000 clients referred to the rehabilitation clinic from 2005 to 2008 participated with complete consent in the study. The highest frequency belonged to opium addicts (85.6%) and the most prevalent addiction type pertains to opium consumption via smoke inhalation (58.2%). The probability rate of AB negative blood type compared to other blood types among the addicts was 6.07 fold the control group. Conclusion: There has been an increasing rate of addiction in bam after earthquake and The substance consumption pattern has moved towards more dangerous methods. The high prevalence of AB blood type brings about a lot of presuppositions for geneticists, epidemiologists, hematologists and all majors in basic sciences. Keywords: Substance misuse, Blood type, Substance rehabilitation centers.