Consumer demand for plant-based alternatives to meat, eggs, and dairy products has surged in recent years, driving expansion across multiple food categories and applications. Key drivers of this trend include allergenicity, sustainability, and the increasing adoption of flexitarian diets. Plant-based eggs serve as a sustainable, animal-free alternative to conventional eggs while supporting healthier food choices. However, plant-derived ingredients have molecular and physicochemical properties that are very different from those of animal-derived ones. Therefore, it is crucial to understand the key properties of plant-derived ingredients and how they can be combined to create structures similar to those in animal products. This chapter focuses on the chemical, physical, and functional properties of plant ingredients and the processing operations that can be used to convert these ingredients into egg analog products. It also provides an overview of the current status of the scientific understanding of plant-based eggs and highlights areas where further research is required.