Abstract The displacement field of an infinitesimal phase boundary dislocation (PBD) loop is first determined from results obtained by Rongved (1955) on the elastic effect of a point force in a two-phase medium. The displacement field of any PBD loop can be derived from a line integral obtained by summing all the contributions of a convenient set of infinitesimal rectangular loops. Explicit expressions are given for the displacement fields of a PBD jog, a semi-infinite PBD dipole and a rectangular PBD loop.