An analytical solution is obtained for the piezomagnetic field generated by a single screw dislocation and its image, representing an infinitely long vertical fault with uniform strike slip that cuts the upper or lower portion of a half-space. The solution is readily extendable to other models of strike-slip faults based on vertical arrays of screw dislocations. For reasonable values of the relevant physical constants the field is predicted to be generally below current levels of detectability. This result is a consequence of the symmetry of piezomagnetization around a screw dislocation, which inhibits regions of intense piezomagnetism near the dislocation from contributing to the external field. ¿ American Geophysical Union 1991