The anisotrpic resistivity of dislocations produced by deformation is measured in high‐purity Al single crystals at liquid‐helium temperature. A network of screw dislocations is produced by twisting a single‐crystal cylindrical Al bar about the [111] direction which was along the axis of the bar. Resistivity parallel to the slip plane is measured by a mutual inductance method and along the crystal axis by a dc potentiometric method using Josephson junctions. Resistivities perpendicular to the specimen axis are found to be greater than those parallel to the specimen axis. The ratio &Dgr;&rgr;ac/&Dgr;&rgr;dc(where &Dgr;&rgr;acand &Dgr;&rgr;dcare the resistivity increments along the directions perpendicular and parallel to specimen axis, respectively) is approximately equal to 1.29.