The first determination of the atomic geometry of the (110) surface of InSb is reported. The structure is determined by comparing dynamical calculations of elastic low‐energy electron diffraction (ELEED) intensities with those measured atT=150 K. Initial candidate structures were obtained from an energy‐minimization calculation and from a kinematic analysis of room‐temperature ELEED intensities. Neither candidate proved fully compatible with the measured intensities so another search for the correct structure was performed using dynamical calculations. This procedure yields as the most probable surface structure for InSb(110) one in which the top layer undergoes both a rigid rotation of 28.8° and a 0.05 Å contraction toward the substrate. The Sb atoms move outward and the In atoms inward, giving a relative vertical shear of 0.78 Å in this uppermost layer. In the second layer, the In moves outward 0.09 Å and the Sb inward 0.09 Å. The resulting structure is analogous to that of covalently bonded GaAs(110) but different from that of ZnTe(110) which exhibits a more ionic bonding. We infer that highly covalent zincblende‐structure compound semiconductors exhibit reconstructions of their (110) surfaces characterized by (1) large bond rotations in the uppermost layer, with the anion moving outward and cation inward, (2) small bond‐length alterations (i.e., a few percent or less), and (3) distortions from the bulk geometry which penetrate at least two atomic layers in from the surface.