Perception of the disease and pharmacotherapy in patients with chronic diseases can be described as individual knowledge, which is defined as the emotional experience of the state of health or disease, which affects the patient's life as a part of this state. Previous studies of the patient's perception of the disease and therapy indicated to its significant impact on the outcome of therapy. The aim of this study was to explore with a qualitative method problem-focused (depth) semistructured interview the patient's perception of the disease and therapy in a sample of patients who have chronic diseases and to study possible differences in perception between the surveyed individuals depending on their characteristics. The research results lead to the conclusion that the attitude of patients towards disease and the treatment depends on a number of factors that determine the patient's positive or negative patterns of behavior and experience of the disease and pharmacotherapy. It can be assumed that the previous attitude of patients, patient education, patient age, understanding of disease, the tendency of patients positive or negative way of thinking, the way the disease manifests itself and the way in which the disease fits the patient's life have a significant impact on making the patient's perception of his disease and pharmacotherapy. Each patient included in the study had a specific idea about his disease and his own story, which is not easy and is not consistent with the story the other patients. Therefore, it is extremely important to create a health professional relationship with the patient based on trust, respect, authenticity, empathy and attachment and it focuses on the whole person because the disease affects every aspect of persons life, resulting in a unique perception of the disease and pharmacotherapy.