The behavior of short fatigue cracks differs from that of long cracks because of greater sensitivity to the microstructure, a greater size of the plastic zone relative to crack length, and a lesser extent of crack closure. Advances have been made in the understanding of the fatigue crack growth process of short cracks, and this understanding has been employed in the development of analytical treatments of short fatigue crack growth. The present paper reviews this progress and also discusses the relevance of short fatigue crack behavior to technologically significant areas.