This paper introduces Pythagorean fuzzy multigroups as an extension of intuitionistic fuzzy multigroups, addressing limitations in uncertainty representation. We establish the theoretical framework for these algebraic structures, deriving fundamental properties including closure under group operations and characterizing intersection and union behaviors. Key results include necessary and sufficient conditions for Pythagorean fuzzy multigroup properties and comprehensive analysis of their algebraic structure. The developed theory provides enhanced tools for decision-making under uncertainty with multiple membership degrees