The Korean Mental Health Act, enacted in 1995, was entirely amended 20 years later and the amendment was passed by the National Assembly plenary session on May 19. 2015. The amended Mental Health Act reflects the recent rapid changes in the mental health environment and contributes one more step toward securing human rights for people with mental illness. However, after review of some major issues, it is doubtful whether there was sufficient discussion on the national mental health policy and whether a national consensus was obtained. This paper describes some problems within the amended Act and discusses several ways to improve the Act. Patients' autonomy and medical paternalism are typical major concerns in the field of medical ethics. Especially for patients with mental illness, it is difficult to maintain a balance between those two concerns because there is often an inability to assign responsibility for those concerns. Therefore, a revised Act should take into account these two concerns. When creating subordinate legislation ahead of the enactment of the amendments on May 30, 2016, establishment of a more reasonable and efficient system is expected ; if there has been sufficient discussion with related organizations and professionals and sufficient consideration of the realities of various medical fields. Such expectations should improve public mental health welfare.