The visuospatial ability referred to as mental rotation has been shown to produce one of the largest and most consistent sex differences, in favor of males, in the cognitive literature. The current study utilizes both a paper-and-pencil version of the mental rotations test (MRT) and a virtual environment for investigating rotational ability among 44 adult subjects. Results replicate sex differences traditionally seen on paper-and-pencil measures, while no sex effects were observed in the virtual environment. These findings are discussed in terms of task demands and motor involvement. Sex differences were also seen in the patterns of correlations between rotation tasks and other neuropsychological measures. Current results suggest men may rely more on left hemisphere processing than women when engaged in rotational tasks.