Pollen–food allergy syndrome (PFAS), also known as oral allergy syndrome, is a common condition affecting individuals sensitized to pollens such as birch, ragweed, and grass. This syndrome arises from immunological cross-reactivity between pollen allergens and structurally similar proteins found in various fruits, vegetables, and nuts. Although typically presenting with mild oral and pharyngeal symptoms, PFAS can occasionally result in severe allergic reactions, underscoring its clinical significance. This review explores the pathophysiology of PFAS, highlighting the molecular mechanisms underlying cross-reactivity and examining the main protein families involved, including those contributing to variations in symptom severity. Current diagnostic approaches, including skin prick testing, specific immunoglobulin E measurements, and component-resolved diagnostics, are discussed. Emerging diagnostic tools and biomarkers with potential to enhance accuracy are also examined. Therapeutic strategies for PFAS primarily focus on symptom management and avoidance of trigger foods. However, novel approaches such as allergen immunotherapy and biologics targeting key immune pathways are gaining traction as potential interventions for more severe or refractory cases. By addressing the diagnostic and therapeutic challenges of PFAS, this paper aims to provide clinicians and researchers with a comprehensive understanding of this condition, fostering improved patient care and the development of innovative treatment strategies.