Purpose In obstructive sleep apnea syndrome (OSAS) many proinflammatory cytokines are released from activated endothelial cells due to repeated decreases in arterial oxygen saturation. Some of these proinflammatory cytokines are involved in the etiology of coronary artery disease (CAD). Although the association between OSAS and CAD is known, risk factors for CAD have not been determined in this patient group. Monocyte chemoattractant protein-1 (MCP-1) is a proinflammatory cytokine that plays a key role in the development of atherosclerosis. In this study, we compared the frequency of MCP1 rs1024610-rs1024611 single-nucleotide polymorphisms (SNPs) in OSAS patients with no comorbidity, OSAS patients with no comorbidity except CAD, and healthy individuals. Material and Methods The study included 301 subjects. Two hundred one patients with OSAS (OSAS only and OSAS + CAD groups) and 100 healthy control subjects underwent polysomnography. MCP1 rs1024610 and rs1024611 mutation frequencies were determined. Results Body mass index, apnea-hypopnea index, triglyceride levels, and mean oxygen desaturation were significantly higher in the OSAS patients than in the healthy population (p < 0.05). In MCP1 rs1024611 SNP analysis, homozygous mutation was significantly more common in the OSAS + CAD group than in the OSAS and control groups (p < 0.001). MCP1 rs1024610 SNP analysis showed no significant differences among the study groups. Conclusion OSAS patients with homozygous MCP1 rs1024611 SNP are at higher risk for CAD. The MCP1 rs1024610 SNP was not associated with incidence of CAD. Patients with OSAS and MCP1 rs1024611 homozygous mutation are more susceptible to CAD and early detection and treatment may significantly reduce mortality and morbidity.