The purposes of this study were to assess dental caries and treatment needs and to investigate some risk factors associated with occurrence of dental caries among drug addicts. A random sample of 60 male subjects of drug addicts was chosen from all admissions to the ward of drug addicts in Maamoura Psychiatric Hospital in Alexandria. A questionnaire was designed and completed by interview with the patients to collect basic epidemiologic data. In addition, examination of dental caries was carried out with a mirror and probe, DMFT & OHI-S indices were measured. Most of drug addicts (78.33%) had decayed teeth. There was a big need for prosthetic appliances for many drug addicts. Out of eight variables entered in the model for multiple regression analysis, dental check up was the best predictor of DMF which means that irregular dental check up was associated with a higher DMF. A drug prevention program should be designed and implemented, offering the appropriate resources and/or assistance to drug addicts to improve safety and health.