Abstract. Background: Physical activity (PA) is recommended by heart failure treatment guidelines. Adherence to exercise prescriptions is low and not much is known about everyday PA in this patient group. Aims: This study describes objectively assessed everyday PA/sedentary behavior in men and women with chronic heart failure and examines associations of potential barriers for engaging in PA, namely fear of physical activity (FoPA), general anxiety, and depression, with indicators of PA and sedentary behavior. Method: In 61 outpatients with heart failure (67.5 ± 10.7 years of age) the impact of FoPA, trait anxiety, and depression on 6-day accelerometer measures was evaluated using linear regression models. Results: Sedentary behavior was prevalent in men and women alike, with lying down and sitting/standing as predominant activity classes during daytime. Men had higher PA energy expenditure (726 vs. 585 kcal/d, Cohen’s effect size d = 0.74) and walked up/down more often (0.21% vs. 0.12% of total PA, d = 0.56) than women. FoPA did not differ between sexes. FoPA, but not anxiety and depression, significantly and consistently predicted less walking up/down independent of covariates (β-values between −0.26 and −0.44, p-values < 0.024). Limitations: The self-selected sample included few women. Medical data were assessed via self-reports. Conclusion: FoPA, but not anxiety and depression, significantly and consistently predicted less walking up/down independent of covariates. These preliminary findings highlight FoPA as a barrier to everyday PA in patients with heart failure.