Phthalides are a class of plant secondary metabolites found predominantly in the family Apiaceae, including species such as celery and dill. These natural compounds possess a wide range of biological activities, making them subjects of extensive research. Chemically, phthalides typically exhibit a bicyclic skeleton with a spiroketal or spiroketone structure, which contributes to their unique physicochemical properties. Phthalides have been associated with various pharmacological effects, including but not limited to relaxation of smooth muscle tissue and inhibition of inflammatory responses. Their application in traditional medicine is also well-documented for treating conditions such as respiratory disorders and cardiovascular issues. In recent years, the potential of phthalides as natural antioxidants and neuroprotectants has garnered significant attention. Due to their diverse biological activities, phthalides are being explored for their therapeutic applications across multiple medical fields. However, further research is necessary to fully understand their mechanisms of action and optimize their use in drug development.