The link between changes in estimated glomerular filtration rate (eGFR) and cigarette smoking was evaluated in Japanese male workers with a 5-year follow-up. We examined the data of 456 Japanese male workers, aged 22-70 years, who were taking no medications, and from this group, 286 men (43.5±8.2 years) were followed for 5-years. Habits of cigarette smoking were obtained during interviews by well-trained staff. The influence of cigarette smoking on eGFR was evaluated. In the first analysis, there was no significant difference in eGFR between subjects with and without cigarette smoking. In the second analysis, eGFR was significantly reduced after 5 years in all subjects. Changes in eGFR in subjects with cigarette smoking (-1.90±12.31 ml/min/1.73 m²) were significantly smaller than those in subjects without cigarette smoking (-4.97±12.05 ml/min/1.73 m²). At follow-up, we found that eGFR was weakly and negatively correlated with the number of cigarettes smoked (/day). The present study indicated that cigarette smoking may be an important modifiable factor for eGFR in Japanese male workers who are not taking any medications.