Work is a major social determinant of health. We conducted a cross-sectional study to explore the association between coronary heart disease (CHD), its risk factors, and the working environment among Japanese male workers. We collected data from 10,572 workers (mean age 49.9) who underwent annual medical check-ups in Toyama, Japan, in 2016. This study included data from health check-ups and questionnaires on medical history of CHD, hypertension, and diabetes, and the use of medication. The working environment included company size and industry categories. Company size was classified into 4 categories according to the number of full-time workers (1-20, 21-100, 101-300, 301-). The industry category was classified into 10 categories. Logistic regression analysis was performed to explore the association. In total, 1.5% of patients had a history of CHD and 31.5% and 11.0% of participants were suffering from hypertension and diabetes, respectively. Compared to workers in a large company, those in a smaller company were more likely to have CHD. Moreover, there was a significant association between CHD's risk factors and working in the transportation industry. Health providers, including medical doctors, should consider employee working environment as a potential risk factor for CHD.