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The  complete  solution  of  a  crack  propagation  problem includes  determination  of  the crack  path.  At  the  present  state  of  the  art  the factors  controlling  the  path  taken  by  a propagating crack  are  not  completely  understood.  In  the  last five  decades  there  have been substantial advances in the understanding and prediction of both macroscopic and microscopic  aspects  of  crack  paths,  largely  through  developments  in  fracture mechanics, and in the application of modern computers and microscopes. As examples, 6 crack  path  topics,  all  of  which  have  a  long  history  and  are  still  of  interest,  are described  briefly.  These  are:  fatigue  crack  paths  in  aircraft  structures,  fractography, fracture toughness testing, mixed mode fatigue thresholds, crack path stability, and the transition from flat to slant crack propagation sometimes observed in thin sheets. The first five of these are illustrated by examples taken from the author’s experience. The papers presented at the International Conference on Crack Paths (CP 2009) show that understanding of crack paths is increasing.