Fruits and vegetables are vital components of a healthy diet, providing essential vitamins, minerals, dietary fibers, and bioactive compounds that contribute to the prevention of chronic diseases such as hypertension, cardiovascular disorders, and stroke. Among various processing techniques, fermentation stands out as a sustainable and natural approach for enhancing the nutritional, sensory, and functional properties of fruits and vegetables. Rooted in ancient culinary traditions, fermentation has historically played a crucial role in food preservation, especially in regions with harsh climates or seasonal scarcity. This chapter explores the diverse world of fermented fruits and vegetables, highlighting their historical significance, cultural diversity, and health-promoting attributes. Emphasis is placed on lactic acid fermentation as a simple yet effective biotechnological intervention for improving product safety, shelf life, and nutritional value. Additionally, the chapter discusses the integration of traditional fermentation methods with modern biotechnological advancements, such as the use of selected starter cultures, to meet the growing consumer demand for minimally processed, nutritious, and flavorful foods. Challenges related to contamination, safety regulations, and quality control are also addressed, providing a comprehensive overview of the potential and limitations of fermentation in the production of functional fruit and vegetable-based foods.