The semaphorins belong to a family of proteins originally shown to be important in axon migration and proper central nervous system development. Recent evidence has demonstrated that semaphorins and their receptors are expressed in tissues outside of the nervous system and represent a widespread signaling system that is involved in regulation of motility in many different cell types. This review specifically addresses the effects of the semaphorins on physiological and pathological angiogenesis and will discuss the most recent findings on the role of semaphorins in head and neck squamous cell carcinoma-induced angiogenesis.