Background: Dysmenorrhea is a common symptom secondary to various gynecological disorders, but it is also represented in most women as a primary form of disease. Pain associated with dysmenorrhea is caused by hypersecretion of prostaglandins and an increased uterine contractility. The primary dysmenorrhea is quite frequent in young women and remains with a good prognosis, even though it is associated with low quality of life. Objectives: The aim of this study is to evaluate of the efficacy and safety of dienogest in the treatment of primary dysmenorrhea: a study in a district-level hospital in Bangladesh. Methods: The cross-sectional observational study was conducted in the Department of Gynae and Obs, Naogaon Sadar Hospital from July 2022 to June 2023. A total of 100 subjects who received DNG (1 mg/day, orally) were included in the study. Data were collected by face-to-face interview and analyzed by appropriate computer based programmed software Statistical Package for the Social Sciences (SPSS), version 24. Results: In this study, most of the patients 43% lies between 21 years to 25 years and body weight of 24% patients were between 51 to 55 kg. In this study, most of the patients 41% body mass index were 18.5 – 24.9 kg/m2. Most of the patients’ clinical symptoms were cramping pain in the lower abdomen (89%), low back pain (86%), pain spreading down to the leg (73%), fatigue (64%). About (56%) adverse effects were body weight gain and irregular uterine bleeding occurred in 35 of 100 cases (35%). Conclusion: Primary dysmenorrhea is one of the most common illnesses in women of childbearing age. When severe, it may interfere with the activities of daily living and may lead to school and work absenteeism. Primary dysmenorrhea is also one of the most underdiagnosed diseases, so clinicians should suspect the diagnosis in a timely manner and provide appropriate treatment.