Unmanned aerial vehicle (UAV) systems for chemical crop protection have experienced significant global growth. They offer precise, efficient, and targeted pesticide application as part of precision agriculture. However, the rapid technological advancement of UAV spraying systems has not been matched by equally fast regulatory development. This has resulted in fragmented frameworks, legal uncertainties, and barriers to widespread adoption. This paper reviews international and national regulations governing UAV-based spraying, with a particular focus on the United States, the European Union, Asia, and Serbia. Special attention is given to differences within the EU. For example, countries such as Hungary and Switzerland have introduced national authorizations for UAV spraying, while others remain limited by general pesticide-use rules. In Serbia, the absence of UAV-specific legislation and the lack of registered pesticides approved for use with UAVs represent critical constraints. This is occurring despite increasing farmer interest and positive field research results. The analysis highlights four key regulatory challenges: safety, environmental protection, equipment certification, and operator training. It also identifies the absence of UAV-specific pesticide registration as a major obstacle to adoption. The study concludes with recommendations to harmonize aviation and plant protection regulations, develop UAV-specific product registration pathways, and adopt international standards. These steps aim to ensure safe, sustainable, and legally secure integration of UAV systems in chemical crop protection.