Selenium (Se) is a necessary trace element that is involved in a number of biological processes in plants, humans, and animals. In horticultural crops, selenium has potential benefits in terms of storage and shelf-life because it has been shown to postpone plant senescence in a many horticultural crop’s species, which may reduce postharvest loss. In fruit, Se may influence the ripening process, most likely due to its anti-senescence and antioxidant qualities, which will improve post-harvest life. Also, selenium can affect the quality of medicinal and aromatic plants and vegetables, leding to a bigger positive impact on human health. Because it has antioxidant properties since it is a cofactor of glutathione peroxidase (GSH-Px) (EC 1.11.1.9), also, selenium helps plants fight off oxidative stress brought on by either internal or external causes by lowering ethylene production. Se is a component for proteins and selenium amino acids. Certain crops’ capacity to store selenium is essential for human nutrition and well-being. Because the food chain starts with plants and finishes with humans. So, a good strategy to boost human Se consumption and maybe improve long-term health is to raise the Se content of plant products, such as medicinal and aromatic plants, vegetables, and fruit crops, without going over the hazardous levels. More research is required to completely comprehend the molecular and biochemical processes that selenium either directly or indirectly influences in fruit tissue ripening and the postharvest stage for all horticultural crops. This chapter will discuss the contents of selenium in vegetable crops, the role of selenium in delaying aging in horticultural crops, and the mechanism for extending the storage period and shelf life of crops.