Summary: The strategy of polytherapy is now widely recommended not only during long-term treatment, but also in the course of initiating therapy. The effectiveness of a therapeutic procedure depends on the patient's adherence during the course of treatment. Poor adherence, non-compliance and non-persistence become the cause of deterioration of disease control, with an increase of hospitalization risk, poor outcome and rise of treatment costs. The combination of two or more active ingredients within a single form of pharmaceutical administration allows to use the synergistic action of drugs, reduce side effects and simplify the treatment regimen. It also significantly improves treatment compliance. Based on a review of the literature and an analysis of treatment recommendations of the most common diseases in elderly patients, the article presents the reasons for deterioration in treatment compliance, and the estimated benefits and limitations of the use of single-pill combinations in the treatment of selected chronic diseases.