Abstract Measurements have been made on the de Haas-van Alphen effect from single crystals of copper containing known dislocation densities. The values of the Dingle temperature x d have been determined at all the principal turning points of de Haas-van Alphen frequency versus angle for all the principal Fermi surface orbits. These measurements have been made over a range of dislocation densities D from 2 × 109 m−2 to 6 × 1011 m−2, and there is satisfactory quantitative agreement in the middle range with existing theory, though lack of precision made it impossible to verify the detailed dependence of x d on D or magnetic field. Additional experiments on the variation of de Haas-van Alphen amplitude and x d with angle near the turning points confirmed further aspects of the theory. However, in one specimen, bulk rotations of regions of the crystal are proposed to account for a relatively large deduced angular spread of crystal orientation. A speculation is made linking these regions to certain features in ...