The relativistic multiresonator magnetron is analyzed in cylindrical geometry, using the two‐dimensional particle‐in‐cell simulation codemagic. Detailed comparisons are made between the simulation results and the experiments by A. Palevsky and G. Bekefi [Phys. Fluids22, 986 (1979)] using the A6 magnetron configuration. Within a constant scale factor, the computer simulations show a similar dependence of microwave power on magnetic field, with dominant excitations in the &pgr; and 2&pgr; modes. In the preoscillation regime, the electron flow in the simulations differs substantially from the ideal Brillouin flow model. In the nonlinear regime, the saturation is dominated by the formation of spokes.