Background: Coronary artery ectasia (CAE) is a rare cardiovascular disorder with unknown mechanisms and related risk factors. The roles played by homocysteine in induction of cardiovascular diseases (CVDs) have also been documented previously. This project was designed to assess the relationship between opium and CAE and coronary artery disease (CAD). Methods: This cross-sectional study was performed on 46 patients with CAE, 30 patients with CAD, and 42 cases without CAE and CAD (controls). Demographic data and information regarding opium consuming and also smoking were collected using a standard checklist. Serum levels of homocysteine, creatinine (Cr), urea, fasting blood glucose (FBG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), and cholesterol were determined. Findings: Statistical analysis revealed that opium consumers were significantly higher in patients with CAD and CAE when compared to healthy controls. Opium increased serum levels of Cr in the normal controls, and decreased HDL in the patients with CAD. Homocysteine serum levels were not significantly different between the groups. Conclusion: The results of study showed that opium addiction was associated with increased risk of CAE and CAD, independent of homocysteine serum levels.