The structure of detonations generated by the flow of a combustible mixture over a wedge is examined numerically. A recently designed, unsplit algorithm which integrates the convective and reaction source terms simultaneously, is employed for the simulations. The chemical kinetics is assumed to follow simple one-step Arrhenius law. Two different geometrical configurations are considered. In the first one, the wedge is assumed to be long enough so that its top corner can not affect the structure of the reaction zone. In the second one, the wedge is short so that this corner can influence the reaction zone. It is observed that for moderate wedge angles the leading shock curves smoothly until it reaches a final angle. A stable detonation and a steady flow-held is established near the wedge. For higher wedge angles, an explosion occurs at the leading shock and the detonation becomes unstable. Grid-convergence studies for both stable and unstable detonations are presented and comparisons with earlier results are made. (C) 2000 by The Combustion Institute.