Recently, the relationship between music and nonmusical cognitive abilities has been highly debated. It has been documented that formal music training would improve verbal, mathematical or visuospatial performance in children. In the experiments described here, we tested if visual perception and imagery abilities were enhanced in adult musicians compared with nonmusicians. In our main experiment, we measured reaction times of subjects who had to detect on which side of a horizontal or a vertical line a target dot was flashed. In the imagery'' condition the reference line disappeared before the target dot was presented. In order to accomplish the task, subjects had to keep a mental image of the position of the line until the dot appeared. In the ''perception'' condition, the procedure and stimuli were the same except that the line remained on the screen until the dot was displayed. In both groups, reaction times were shorter for horizontal compared to vertical discrimination, but reaction times were significantly shorter in musicians in all conditions. Moreover, discrimination on the vertical dimension, especially in imaging condition, seemed to be greatly improved on the long term by musical expertise. Simple and choice visual reaction times indicate that this advantage could only be partly explained by better sensorimotor integration in adult musicians.