A blood clotting disorder leading to thromboembolic diseases represents a significant public health issue due to the elevated mortality it results in, both in developed countries worldwide and in Croatia. The treatment of a chronic disorder that is "silent" and imperceptible to patients yet exceedingly perilous heavily relies on the adherence of the subjects involved. As a more recent generation of medications, Direct Oral Anticoagulants (DOACs) are increasingly prescribed owing to their superior pharmacokinetic profiles compared to older drugs. The objective of this dissertation was to investigate the most common DOAC used in the therapy of subjects, identify the ailments afflicting the subjects, and assess the adherence of subjects to DOACs. The study aimed to explore attitudes and beliefs about medications and illnesses in general, as pivotal factors influencing adherence. Additionally, it aimed to examine the socio-demographic and clinical factors influencing both medication adherence and attitudes and beliefs about medications.A crosssectional observational study was conducted, involving subjects under treatment with some form of direct oral anticoagulant. Adherence was gauged using the Medication Adherence Report Scale (MARS-5), while attitudes and beliefs about medications were assessed using the Beliefs about Medicines Questionnaire (BMQ). The study enrolled 63 participants, with 30 females (47.6%) and 33 males (52.4%). The median age was 73.5 years (interquartile range 61.5-78). The youngest participant was 25 years old, and the oldest was 91 years old. By completing the MARS-5 questionnaire, participants demonstrated high adherence, as indicated by the mean score of 24.11±1.493. The most frequent cause of non-adherence was skipping doses and forgetting medication. Other sociodemographic and clinical data did not exhibit significant influence on adherence.Participant attitudes and beliefs about medications were notably positive. A statistically significant difference was identified between highly adherent patients and those with slightly lower adherence in the "Concerns about Medications" scale of the Specific section (p=0.008). Furthermore, differences were observed between individuals younger than 65 and those aged 65 and older in the "Necessity" scale of the General section (p=0.036), and between individuals with different educational levels for the "Perceived Sensitivity to Medications" scale of the General section and the "Necessity" scale of the Specific section (p=0.008; p=0.019).This research has elucidated certain factors influencing medication adherence, attitudes, and beliefs about medications, as well as the mutual impact of attitudes and beliefs on adherence. Enhanced comprehension of the factors affecting adherence, attitudes, and beliefs can facilitate their modification and improvement.