The aim of this study was to investigate the prevalence and prognostic value of coronary artery disease (CAD) and heart failure (HF) in patients with idiopathic pulmonary fibrosis (IPF). Thirteen hundred and fifty-eight patients with interstitial lung disease [851 (62%) males, mean age: 68 ± 10 years] were retrospectively analyzed. CAD was defined as (1) the presence of a clinical diagnosis of angina pectoris, (2) clinical diagnosis of a myocardial infarction, and (3) coronary angiography showing ≥ 1 vessel with a stenosis of > 75%. The definition of HF was made according to the modified Framingham criteria. Compared to the non-IPF group (n = 790), the IPF group (n = 568) had a significantly higher prevalence of CAD (9.3% vs. 4.4%, p < 0.001) and HF (8.2% vs. 3.7%, p < 0.001). During a median follow-up of 1.6 years, 152 deaths were identified. The patients with HF had a significantly worse prognosis than those without HF both in the non-IPF group and IPF group (both p < 0.05). However, the prognosis did not significantly differ between the patients with CAD and those without CAD both in the non-IPF group and IPF group. The presence of HF was an independent predictor of death in the IPF [hazard ratio (HR) 3.67, 95% confidence interval (CI) 1.57-8.56, p = 0.0025] and non-IPF (HR 5.07, 95% CI 1.44-17.86, p = 0.011) patients. The prevalence of CAD and HF was significantly higher in IPF than non-IPF patients. In addition, the presence of HF was a significant prognostic factor for both IPF and non-IPF patients. These results indicated that the importance of HF as a comorbidity for patients with ILD.