Blistering lesions (vesiculobullous lesions) of the oral mucosa and skin are a diverse group of mucocutaneous disorders characterised by various clinical and pathological features. These lesions arise from a wide range of causes, including infectious, inflammatory, drug-induced, genetic, and autoimmune conditions. Because of their potential association with significant morbidity and mortality, precise diagnosis is crucial for effective management and improved patient outcomes. This chapter stresses the importance of accurate clinical and histopathological assessment in differentiating these disorders to facilitate appropriate therapeutic interventions.