Dislocations have been studied in YIG by transmission electron microscopy. Loops are found to have (a/2) ⟨111⟩ Burgers vectors whereas dislocation segments may have (a/2) ⟨111⟩ ora⟨001⟩ ones, the latter resulting from the attractive reaction of dislocations with (a/2) ⟨111⟩ Burgers vectors. Owing to the large unit cell of YIG, experimental imaging conditions prevented from concluding on the possibility of dislocation dissociation.