Although mental rotation ability has been researched broadly in cognitive psychology and neural studies, development of mental rotation and the effective method of training are rarely considered as an area of study in the education field. We aimed to study the development of mental rotation through the training program by three-dimensional twisty puzzle in two groups of school students (8-9-years, n=13 and 11-12-years, n=17). This quasi-experimental study with the pre-test post-test design was conducted at the Tehran international school girls. The students' mental rotation ability was evaluated using the well established testing methods (VMRT; Vandenberg & Kuse, 1978). After the initial test and training program (twelve 60-minute sessions), the results of the within-subject ANOVA indicated that 8-9-years school children were incompetent after post-test through follow-up session, whereas the 11-12-years school students did make gain in post-test and three months after training program. The study findings suggest that development of MR ability by three-dimensional puzzles can be wielded throughout extra school training program among primary school students.