Movement time to align a cursor with targets on a computer screen a mouse was examined across settings of gain and target size. Empirical evidence was sought in light of previous suggestions that performance declines observed at higher gains can be explained by decreased effective cursor resolution, not gain per se. We tested this hypothesis by holding the effective cursor resolution constant while systematically varying gain and target size. Analysis of movement times showed a significant gain effect as a function of target size. Specifically, movement time increased with gain at the smallest target size (i.e. 1.5 mm) but decreased with gain at the largest target size (i.e. 12 mm). These results do not support the no-effect of gain hypothesis and suggest that target size is an important factor in determining the effects of gain on mouse movement performance.