Plasma etching of group III-V semiconductors used in electronics and optoelectronics is reviewed. In cases where the active region width is large (>3 microns), wet etching provides a simple, effective method for pattern transfer. However, for more demanding structures and for a greater degree of control during device fabrication, plasma etching methods offer advantages. Crucial requirements for plasma etching of III-Vs include the need for equirate removal of etch products to maintain near-surface stoichiometry and avoidance of ion-induced lattice damage, which degrade the performance of devices made from these materials. Almost all plasma etching of compound semiconductors occurs in the ion-assisted regime.