This comprehensive study delves into the inheritance laws of Ukraine and Poland, shedding light on their common features and distinguishing factors. In an era of increasing cross-border estates and globalized family structures, understanding the intricacies of inheritance laws in these two nations is of paramount importance. The analysis begins by exploring shared legal terminology and concepts, such as "testament," "intestate succession," and the emphasis on family and kinship in determining inheritance rights. Both countries provide provisions for disinheritance under specific circumstances and establish succession rights for spouses and children, underscoring the significance of familial relationships. However, significant disparities emerge in several key areas. Variations in inheritance taxation structures are evident, with Ukraine employing preferential tax rates for close relatives, while Poland bases taxation on asset value. Formalities for creating valid wills diverge; Ukraine allows for simple handwritten wills, while Poland demands more formal notarial requirements. Ukraine's forced heirship provisions safeguard certain family members' minimum entitlement to the estate, a contrast to Poland's absence of strict forced heirship. The study underlines the influence of socio-economic factors, with Ukraine's post-Soviet heritage and Poland's transition from communism shaping their respective legal landscapes. It offers crucial policy recommendations, including the harmonization of inheritance taxation structures, balanced forced heirship provisions, and guidelines for cross-border estate planning. In an increasingly interconnected world, the need to harmonize inheritance laws becomes evident, ensuring fairness, predictability, and the protection of individual and familial interests. This research contributes to a deeper understanding of inheritance laws in Ukraine and Poland, providing valuable insights for individuals, legal practitioners, and policymakers navigating cross-border estate planning and succession cases.