Non-communicable diseases such as cardiovascular diseases, cancer, chronic respiratory diseases, and Diabetes Mellitus, contribute significantly to global illness and mortality rates, including in Thailand. Collaborative efforts are crucial for effectively managing these diseases and ensuring patients' adherence to medication. However, over half of the patients struggle with following the prescribed treatment regimen, leading to complications, disability, premature death, and increased healthcare costs. Existing knowledge on medication adherence for chronic non-communicable diseases is primarily derived from foreign social and cultural contexts, which may limit its applicability to Thai patients. Additionally, there is a lack of in-depth studies on medication adherence from the patients' perspective in the Thai community. Therefore, this study aims to explore and understand the meaning and experiences of medication adherence in Thai patients with chronic diseases, as well as the conditioning factors that influence adherence. This research applies qualitative methodology to study at chronic disease and psychiatric clinics at Wang Thong Hospital and Nong Phra Subdistrict Health Promoting Hospital. Data collection involves in-depth interviews, observations, and studying medical records of 24 registered patients. Inclusion criteria include 1) patients with high blood pressure [hypertension: HT], and/or abnormal blood lipid levels [dyslipidemia: DLP], and/or myocardial infarction [MI], and/or chronic heart failure [CHF], and/or stroke, and/or diabetes [DM], and/or chronic obstructive pulmonary disease [COPD], and/or depression. 2) have received treatment for chronic diseases for at least one type of medication from either the Chronic Disease Clinic or the Psychiatry Clinic at Wangthong Hospital or Nong Pra Hospital continuously for a minimum of one year. 3) able to communicate in the Thai language. 4) voluntarily participate in the research study after receiving informed consent. This study interviewed 8 repeat informants, totaling 32 interviews. Data analysis utilizes Colaizzi's method (Colaizzi, 1978 cited in Sanders, 2003) and ensures trustworthiness using Lincoln and Guba's framework (Lincoln & Guba, 1985). The study identified five themes regarding experiences of medication adherence in patients with chronic diseases in the community. The first theme is patients' expectation for better life through treatment and medication adherence. Patients follow doctor's instructions to recover or alleviate symptoms and return to normal life. However, when treatment outcomes, including the effects of drug use, are unsatisfactory or when side effects occur, patients may engage in non-adherent behaviors. This means that the treatment and medical regimen recommended by physicians do not meet their expectations or needs. They may also seek additional treatment methods, such as visiting private and reputable clinics and using supplements. The second to fifth themes involve conditioning factors that affect medication adherence within the Thai context. These themes cover concerns about consistent medication adherence, self-management, family support, and building relationships with healthcare professionals for effective treatment, as well as addressing specific sub-issues.