A patient (C.B.) with severe left visuo-spatial neglect and hemianopia after right hemisphere stroke was tested on three conditions of a clock-drawing task. Either on spontaneous drawing or when the number sequence was provided by the experimenter, C.B. drew a clockface with left-sided numbers transposed to the right side of the dial. By contrast, when each number was drawn on a separate dial, its location was correct and there was no transposition. Directional hypokinesia or a representational deficit cannot explain these effects. It is proposed that a deficit in disengaging attention from right-sided visual stimuli plays a critical role in some forms of number transpositions.