Objective: Mental rotation in adults has been linked to performance in mathematic functioning and to a male advantage. This study examines whether gender dimorphism is present in young children using developmentally appropriate computer-delivered stimuli. Method: Forty children (19 boys) ages 6–12 completed a 2-subtest WASI (Vocab/Matrices) Estimated IQ, WJ-III Math Calculation, and an experimental mental rotation paradigm. Adaptations of the Shepard-Metzler (1971) mental rotation stimuli were made appropriate for younger children by using fewer blocks configured into progressively difficult items with three multiple-choice options. Results: No gender differences in performance on any variable of interest, IQ, math, or mental rotation were found. Mental rotation was found not to be related to mathematics performance. WASI Matrices explained 17.2% of the variance in MR number correct (β = .420, p = .010) and 13.3% of the variance in response time for correctly answered items with age and estimated Verbal IQ controlled. WASI Vocabulary did not explain any significant variance in mental rotation number correct or response time. Notably, WASI Matrices explained significant unique variance of 13% (β = .370, p = .019) in mathematics performance when estimated Verbal IQ was controlled. Conclusion(s): In younger children, the MR task may be a proxy for some aspects of nonverbal problem solving, but not necessarily those related to mathematics performance. The developmental differences seen in MR performance and it's relation to gender and mathematics may be more strongly influenced by cultural and environmental factors related to preferred and/or primed attention to mathematics.