This chapter discusses the nutrient content of various processed and treated green vegetables. In some cases, the nutrient content of processed vegetables has been reported as being greater than that of fresh (raw) vegetables. It was found that the processing and heat treatment has both positive and negative effects on the nutrient content of vegetables, which depend on different factors like altering conditions for processing and morphological and nutritional attributes of that particular species. The chapter reviews the effects of thermal processing on nutritional components of green vegetables. Vegetables are the main source of fiber, which is classified into two classes: soluble fiber, and insoluble fiber. Vegetables contain some organic acids such as citric, malic and oxalic acids are the predominant acids found in vegetables. Thermal processing is used primarily for sterilization of foods since the first scientific evidence witnessed in 1920 when Bigelow and Ball developed the thermal processing concept for the minimum safe sterilization process (MSSP).