Plastic buckling of clamped annular plates subjected to in plane torsional moments is analysed by analysing the bifurcation of equilibrium. In the analysis, the effect of radial and circumferential stresses induced by clamping the annular plates on the critical buckling loads is taken into account. The results show that the critical torsional moments are substantially lowered because of the presence of the induced stresses and that the J 2 flow theory predictions for the buckling loads can be in agreement with the experimental results.