Objectives The purpose of this study is to explore the relationship between the interactions of CYP2C19 gene polymorphisms and several environmental factors and oesophageal squamous cell carcinoma (OSCC). Methods In a case-control study of OSCC patients (n = 350) and healthy controls (n = 350), we investigated the roles of polymorphism in the CYP2C19 gene by the use of polymerase chain reaction - restriction fragment length polymorphism (PCR – RFLP) analysis. Results The CYP2C19*3 AG+AA genotype was significantly more prevalent in OSCC patients (10.0% versus 3.43%; P<0.01). Multiple logistic regression analysis showed drinking (OR: 5.603, 95% CI: 3.431–11.112; P = 0.005) and smoking (OR: 4.341, 95% CI: 3.425–10.241; P = 0.001) was the independent risk factor of OSCC respectively, and there were significant interaction between CYP2C19*3 and drinking (OR: 8.747, 95% CI: 6.321–18.122; P = 0.009). Conclusions The CYP2C19*3 polymorphism and OSCC were synergistically and significantly associated in Chinese Han patients.