Ethylene is a simple gaseous plant hormone produced by higher plants and also by bacteria and fungi. Its physiology is continuously going through new developments in cellular, molecular biology and genetic engineering of plants. The understanding of the role and function of ethylene in plant growth, development, fruit ripening and scenecense has been improved through new works and methodologies. Studies on ethylene and developmentally-regulated processes in ripening of climactic fruits and a better knowledge on ethylene receptors and antagonists that prevent an ethylene response open possibilities of particular value in horticulture and postharvest. This text publishes advances on the different topics.