Aim of the study was to analyze the factors affecting treatment adherence in working-age patients with myocardial infarction (MI). Material and methods. During hospitalization, data of 150 patients with MI were collected using medical records and questionnaires. Social treatment readiness was assessed using the S.V. Davydov method with the calculation of treatment adherence (TA) score. After 6 months, the vital status, frequency and causes of hospitalizations, intake of the main groups of drugs, achievement of cardiovascular health target, frequency of regular medical check-up and the type of specialist conducting it were analyzed. In conclusion, the factors affecting the TA score were identified, as well as factors related to the achievement of cardiovascular health targets. Results. 6 months after MI, 4 (2.7 %) patients died due to cardiovascular diseases, 24 (16 %) were hospitalized. The inpatient TA score was 5 (4; 8) (median (lower quartile; upper quartile)), in 79 (52.6 %) patients it was low. The adherence of the surviving patients to treatment after six months was high: 142 (97.3 %) were taking disaggregants, 138 (94.5 %) were taking beta-blockers and reninangiotensin-aldosterone system inhibitors, 139 (95.2 %) were taking statins. However, only 56 (69.1 %) patients achieved target levels of low-density lipoproteins (LDL); 118 (80.8 %) patients achieved target levels of blood pressure, 95 (65.1 %) patients achieved target levels of heart rate (HR) at rest. Only about half (56.8 %) of patients with MI had regular medical check-ups, and only 38.5 % visited cardiologist. Patients who did not achieve target levels of LDL and HR had lower baseline TA score (p = 0.038 and p = 0.029, respectively), they showed up to fewer regular medical checkups after MI (p < 0.001). In patients who did not achieve target HR, the indicator of willingness to pay for treatment was low (p = 0.041), and regular medical check-ups were 4.2 more likely to be performed by a paramedic (p = 0.021). High-score TA was associated with the patient`s lack of propensity for social isolation, high social awareness, trust in the therapeutic treatment, willingness to pay for treatment, high sociability, dyslipidemia in history, the absence of passive smoking during the year, undergoing stage 2 of stroke recovery, working at the time of MI or the late age at onset of alcohol consumption. Low TA score was associated with the patient being the resident in the city, Q-wave MI, and a long-term smoking. Conclusions. Among the factors affecting treatment adherence in working-age patients with MI, certain indicators such as medical and social treatment readiness throughout hospitalization, and social, economic and clinical anamnestic characteristics are highlighted. The identification these factors should be implemented in real clinical practice to improve secondary prevention and outpatient follow-up.