Fundamental characteristics, general physical and mechanical behavior, and the recent developments in the knowledge of hot-melt adhesives (HMAs) are introduced. The current research and development status for HMAs is reviewed, with an emphasis on the development of new types/generations of HMAs. In particular, some crucial issues and challenges on the technological improvements and the materials development are discussed. On the basis of the current predicted shortage of energy resources and environmental concerns, prospective research on the development of green HMAs is suggested.