Flashes presented around the onset of a saccade are mislocalised in the direction of the saccade target. In order to evaluate whether uncertainty about the moment of the flash contributes to this peri-saccadic mislocalisation, we examined whether the mislocalisation is influenced by an irrelevant tone that was presented at different moments around the time of the flash. When a tone was presented before the flash, the time course of the mislocalisation was shifted, as if the flash had been presented earlier. The amplitude of the mislocalisation was not influenced by the tone. To explain the temporal shift, we used a model based on the following reasoning. If the flash and tone are judged to occur simultaneously, the perceived time of this event will be between the time of the flash and that of the tone. If we describe the chance of the flash and tone being regarded to occur simultaneously by a Gaussian with a temporal uncertainty (SD) of 43 ms, the resulting model could describe the data well if the tone is considered to contribute at least 25% to the estimated timing of the flash. We conclude that temporal uncertainty is indeed a factor in peri-saccadic mislocalisation.