The principle of mandatory prosecution (MP) is respected, extensively applied, and has a long-standing tradition in continental European countries, and it is highly valued in socialist nations. However, in recent decades, there has been a notable shift in its implementation within these countries, with numerous studies reflecting this change by presenting diverse perspectives on the necessity to alter, modify, or preserve this principle. One of the primary aims of this paper is to examine the scope of research on responses to MP and the main reasons for maintaining or renewing MP highlighted in related publications. This paper employed a systematic literature review (SLR) to search the Scopus and Web of Science (WoS) databases, compiling a total of 28 papers spanning 50 years. These articles cover a wide range of countries and diverse jurisdictions currently applying either MP or discretionary prosecution (DP) principles. Furthermore, the literature review includes various arguments and discussions on how countries should respond to MP. Findings indicate that MP persists due to its enduring values, such as legality and equality, alongside its significant role in safeguarding the criminal justice system against arbitrariness and abuse of power. Our paper also reveals that the tendency to renew or replace MP is influenced not only by conflicting opinions but also by political factors and the consideration of victims’ discretion in certain offenses, particularly in cases of domestic violence. Additionally, three options for reconciling MP and DP principles are proposed to aid readers in understanding the transition process between these two fundamental principles. Ultimately, the paper advocates for further research on MP in current or former socialist countries, where applicable.