The World Health Organization (WHO) defines adherence as “the extent to which a person’s behavior – taking medication, following a diet, and/or executing lifestyle changes – corresponds with agreed recommendations from a health care provider .” Therapeutic adherence is determined by persistence and compliance of medication intake. Persistence describes the length of time a patient continues taking medication and is measured as the time from treatment initiation to treatment completion or discontinuation. Compliance describes how well a patient is taking his or her medication, that is, to what extent a patient follows a treatment regimen and any associated dosing requirements .” According to the WHO, in developed countries, adherence to longterm therapies for chronic diseases averages 50 percent . “Research in the medical and social sciences has demonstrated that across a wide variety of settings and treatment recommendations, roughly half of all medical patients in the United States do not adhere to, or comply with, their physicians’ advice. Close to 40% of patients take prescribed medication incorrectly or not at all .” For more than three decades, researchers have sought to understand and improve patients’ understanding to medication regimens for the treatment of illness . Their findings suggest a number of strategies that healthcare providers can use to improve patients’ understanding. A physician, nurse practitioner or other authorized healthcare provider who writes a prescription usually intends that the patient follows it. However, given the extent of poor understanding, it is unlikely that any prescriber will see perfect adherence by all patients . According to above literatures, misunderstanding of medical prescription still occur in community and it may cause complications upon them such as antibiotic resistance and recurrence of the disease. Therefore, assessment of understanding of medical prescription is still needed. This study aims to explore understanding of medical prescription from health care provider to the patients and its influencing factors upon them. Moreover, this study may support important facts for further plan in medical prescription.