Background: The Prostate cancer is the 2nd most common cancer worldwide for males, and the 5th mostcommon cancer overall, with an estimated 900,000 new cases diagnosed in 2008 (14% of the total in males and 7%of the total overall) aim of this study was to assess some of the most proposed environmental factors influencingthe incidence of prostate cancer among Iranian men. Smoking, opioids, occupation and living location wereconsidered as studied risk factors of the prostate cancer in this research. Material and methods: Two groupsof affected men with prostate cancer and controls aged 50-75 years referred to medical clinics were subjectsin this case-control study. Living and working place, smoking and drug consuming habits were assessed forany associations with prostate cancer. Results: The largest number, of patients, in order, belonged to Tehran,provincial capitals, major industrial cities, small towns and villages, respectively. The disease showed links withsmoking and drugs with a significant difference between controls and patients (P value <0.0001). Conclusions:Our recent evidence duplicates previously done researches confirming the serious adverse effects of smokingand drugs on the prostate cancer occurrence in Iranian men. Living place bearings some hazardous behaviorswhich increases the rate of diseases as well as advanced chance for associated cancers like prostate.