The objective was to study the relationship between cyclin D1 gene (CCND1) polymorphism and lung cancer in the Chinese population. Blood samples of 182 cases and 185 controls were collected from a hospital based case-control study. PCR-SSCP was used to examine the G/A polymorphism in exon 4 of CCND1. The results showed that the frequencies of the CCND1 AA, GA and GG genotypes were 31.3, 46.7 and 22.0% respectively in cases, and 21.1, 53.0 and 25.9 respectively in controls. Adjusted by age (in years), sex and smoking status, multivariate logistic regression analysis showed that the AA genotype was associated with a significantly increased risk (OR = 1.87, 95% CI 1.01-3.45) for lung cancer. In the stratification analysis, the CCND1 AA variant genotype was associated with increased risk in individuals who were </=50 years old (OR = 3.23, 95% CI 1.17-8.96) and males (OR = 2.46, 95% CI 1.18-5.10). According to histological types, there was significantly higher frequency of AA genotype in squamous cell lung cancer than that in controls (OR = 2.92, 95% CI 1.07-8.03). In conclusion, it is suggested that the CCND1 G/A polymorphism is associated with the early onset of lung cancer in men and contributes to susceptibility to lung cancer, especially squamous cell cancer, in this population.