The aim of this study was to explore the readiness for physical activity (PA) and its related factors in patients with heart failure. This cross-sectional study included 163 patients with heart failure (mean age 66 ± 16, 50% female). The ability to safely engage in PA was assessed with the PA Readiness Questionnaire (PAR-Q). Psychological readiness was measured using two questionnaires, namely: Exercise Self-efficacy Scale and the Motivation for PA and Exercise/Working Out. A multivariate analysis of covariance was conducted to test the effect of background variables on readiness for PA. 64% (n = 105) of patients reported not being able to safely engage in PA, 80% (n = 129) reported low self-efficacy, and 45% (n = 74) were extrinsically motivated indicating external factors drove their motivation. Factors that positively influenced the PA readiness included lower age (p < 0.01), being male (p < 0.01), being married (p < 0.01), having higher education (p < 0.01), being in NYHA-class I compared with II (p < 0.01), less time since diagnosis (p < 0.01), lower BMI (p = 0.02), and not suffering from COPD (p = 0.02). Prior to recommending exercise, assessment of safety to engage in PA along with self-efficacy and motivation in patients with heart failure is essential.