There are some studies on the knowledge, beliefs, and perceptions of patients about acne vulgaris, however, there is no sufficient data on patients' beliefs about oral isotretinoin treatment (OIT). The aim of this study was to assess the knowledge, beliefs, and perceptions of the patients with acne vulgaris about the therapy of OIT and its side effects. A total of 214 patients with acne vulgaris in our outpatient clinic were included. Patients who were planned to treat with OIT were asked whether they had information about the treatment and its side effects. It was noted whether the patients accepted treatment after being informed both verbally and written about the OIT details. The study consisted of 133 female and 81 male aged 12-57 years. Most of the patients (78%) stated that they had heard of OIT. The most common source of the information on isotretinoin therapy was friends (57.6%). The dryness was the best-known side effect. While 86.4% of patients (n: 185) accepted OIT, the group (14.4%) stated that "I have knowledge about side effects." And refused to use the treatment. Most of the patients agreed to the treatment after explanation of dermatologist. Patients may be educated and informed via reliable medical sources to prevent bias and improve compliance to the treatment.