Health risks within prisons are well known and have worsened with the 2019 coronavirus pandemic (COVID-19), becoming a public health emergency. To date, there are more than 10 million inmates in the world; in most cases, conditions are bad and health care is scarce. A SARS-CoV-2 outbreak inside a prison is extremely rapid. The aim of this systematic review was to analyze all possible prevention techniques to reduce the risk of COVID-19 related infection within prisons. A systematic review of the literature was performed according to the PRISMA guidelines. Scopus, Web of Science, PubMed, and Google Scholar were used as search engines from 1 January 2020 to 1 November 2021 to evaluate the prevention of COVID-19 in prisoners. A total of 1757 articles were collected. Of them, 486 duplicates were removed. A total of 1250 articles did not meet the inclusion criteria. In conclusion, 21 articles were included in the present systematic review. From this analysis, it emerged that the most common COVID-19 prevention methods were the screening of the entire population (prisoners and workers) inside the prison through swab analysis and the reduction in overcrowding in prisons. Few studies concerned the prevention of COVID-19 infection through vaccination and the implementation of quarantine. To our knowledge, this is the first systematic review that evaluates the prevention of COVID-19 within jails and the real effectiveness of all possible methods used and published in the literature. Finally, a very useful strategic protocol is provided to reduce the incidence of infection and to control and manage COVID-19 in prisons.