Objective: To explore the association between the ability of self-care agency with some basic conditioning factors related to the agency in people with heart failure of Medellin (Colombia)Material and methods: A cross-sectional study was conducted in a convenience sample of 266 people with heart failure of two hospitals in the city of Medellín (Colombia) from 2007 to 2011. An instrument which included socio-demographic variables, social support and clinics was used. To evaluate the ability of self-care agency was used the version of the Appraisal of Self-care Agency Scale-ASA of Evers, validated in Spanish by Gallegos.Results: The self-care agency ability was deficient in 47, 0% of the participants. The higher ASA scores were found in people 51 years old, higher socioeconomic levels, married, technical or university education, those who practiced leisure activities, with any kind of social support and those with functional class I and ejection fraction of 40%. Logistic regression analysis showed that sufficient self-care agency is related to ejection fraction, age and marital status.Conclusion: The self-care agency ability was deficient in the middle of the participants. Basic conditioning factors, like ejection fraction, age and marital status, were associated with better self-care agency ability.