Introduction and Objectives: Cardiac insufficiency is a major health problem with a social, economic and human impact. It causes a serious limitation in the quality of life of patients. An important aspect in the patients’ evolution is their adherence to the treatment. In primary health care, not all the professionals are familiar with the therapeutic procedures. This study was aimed at determining the factors linked to the treatment and therapeutic adherence of patients diagnosed with cardiac insufficiency. Methods: a cross-sectional descriptive study of the total amount of patients suffering from cardiac insufficiency (56) in the family doctor’s consulting room Nº 3 of Santa Clara Polyclinic was carried out. The sources of the collected data were the medical certificates, the individual and family medical histories and the personal interviews. Results: cardiac insufficiency prevailed in the age group between 70 and 79 years of age (44,6 %), and among women (66,1 %). The total adherence to the treatment prevailed with 78.6 percent, and the incomplete adherence was 21,4 percent. The most common functional classification were class II (46,4 %) and class III (37,5 %). The digitalics and diuretics were the most common medication (82,1 % and 71,4 %respectively). There was an incorrect treatment in 39.3 percent of the cases and inadequate knowledge in 45 percent of the doctors. Conclusions: The therapeutic adherence of the patients was not linked to age and gender. The incomplete adherence was higher in patients with an inadequate follow up, in functional classifications II and III. The digitalics and diuretics were the most commonly used medications. There was a wrong treatment in a large number of patients, as well as inadequate knowledge in the professionals.