Medical malpractice leads to medical criminal liability and claims. The national data of medical criminal liabilities across various specializations, before and after the Medical Care Act amendment, was lacking in Taiwan. The aim of this study is to clarify the impact of the law amendment. A comprehensive retrospective analysis of medical crimes was conducted from January 2001 to December 2020 in Taiwan. The number of medical criminal litigation, defendants, people who plead guilty, conviction rate, and punishment sentences were analyzed. Additionally, the number of practicing physicians in the year was used as the baseline to determine the rate of the accused and guilty rate per 10,000 physician-years, respectively. From 2001 to 2020, there were 249 criminal litigations of medical professionals, which gave rise to 335 defendants. The proportion of defendants by specialization was 19.1% in internal medicine, 26.3% in surgery and orthopedics, 11.9% in obstetrics and gynecology, 3.3% in pediatrics, 25.7% in physicians (who were not related to the aforementioned 4 specializations), and 13.7% in non-physician staff. After the amendment to the Medical Care Act in 2017, the accused rates per 10,000 physician-years decreased significantly in aggregate and by specialization between 2016 and 2020; the guilty rate per 10,000 physician-years during 2016 to 2020 was the minimum, compared to the past. The amendment to the Medical Care Act in 2017 reduced the number of vexatious criminal proceedings. The amendment also reduced criminal liabilities by reducing the guilty rate during 2016 to 2020, compared to the previous period.