•The prevalence of ischemic heart disease was higher in bipolar disorder.•The incidence of ischemic heart disease was higher in bipolar disorder.•Younger bipolar patients had higher relative risk of ischemic heart disease. This study investigated the national prevalence and incidence of ischemic heart disease and associated factors among Taiwanese patients with bipolar disorder. We used a random sample of 766,427 subjects who were ≥18 years old from the National Health Research Institute database in 2005. Subjects with at least one primary diagnosis of bipolar disorder or ischemic heart disease were identified. We compared the prevalence and incidence of ischemic heart disease in bipolar patients and the general population in 2005 and the same cohort from 2006 to 2010. These associated factors with respect to ischemic heart disease among patients with bipolar disorder were also analyzed. The prevalence of ischemic heart disease in patients with bipolar disorder was 1.69 times higher than in the general population (7.85% vs 4.67%; odds ratio 1.69; 95% confidence interval, 1.41–2.03) in 2005. The average annual incidence of ischemic heart disease in patients with bipolar disorder was also 1.60 times higher than in the general population (2.02% vs 1.24; risk ratio 1.60; 95% confidence interval, 1.36–1.90) from 2006 to 2010. The higher prevalence of ischemic heart disease among bipolar patients was associated with increased age, diabetes, hypertension, and antidepressant use. Patients with bipolar disorder had a significantly higher prevalence and incidence of ischemic heart disease than the general population in both sexes, especially at younger ages. Among patients with bipolar disorder, older age, and hyperlipidemia were risk factors of ischemic heart disease.