Background: Heart failure (HF) is one of the leading causes of morbidity and mortality in the elderly. Early recognition, treatment, and elimination of potentially modifiable risk factors for HF are crucial for improving both survival and health-related life quality in those with HF. We aimed to investigate whether or not there is an association between olfactory function and the presence and severity of ischemic HF. Methods: The study included 40 patients with ischemic HF and 40 controls with coronary artery disease but without HF. All patients and controls underwent detailed physical and echocardiographic examinations. The Sniffin’ Stick test was used to evaluate olfactory function. Results: Threshold-discrimination-identification (TDI) score was significantly lower in the patients with HF than in the controls (16.4 ± 7.8 vs. 33.3 ± 5.2, p < 0.001). When patients with ischemic HF were categorized according to New York Heart Association (NYHA) class, the TDI scores were significantly higher in the patients with NYHA class 1 HF compared to those with NYHA class 3 HF (23.4 ± 0.9 vs. 8.8 ± 7.0, p < 0.001).We also found a significant negative correlation between the TDI score and NYHA class (r = -0.769, p < 0.001) and a positive correlation between the TDI score and left ventricular ejection fraction (r = 0.902, p < 0.001). Conclusions: Olfactory function was severely impaired in the patients with ischemic HF in this study. In addition, olfactory dysfunction in the patients with ischemic HF was significantly correlated with the severity of HF.