Background <p>Switching from a static to a dynamic balance condition may influence cognitive task performance, such as mental rotation.</p> Aims <p>This investigation aims to determine the effects of unstable equilibrium on mental rotation tasks with object-based 3D cube and human.</p> Methods <p>Thirty-five collegiate female athletes consented to participate in the study, where tasks related to 3D mental rotation of cubes and/or human figures, paired with balance exercises (either frontal and/or sagittal) on a wobble board in response to seven stimuli, corresponding to rotation angles of 45°, 90°, 135°, 180°, 225°, 270°, and 315°.</p> Results <p>Findings from the ANOVA provided significant insights into the cognitive processing involved in mental rotation tasks under different angles, conditions, and with different objects among unstable equilibrium by decreasing both response-time and error-percentage (i.e., frontal balance <i>p</i> = 0.002–0.001; <i>d</i> = 1.318–2.004 and <i>p</i> = 0.01–0.001; <i>d</i> = 1.120–2.140, sagittal balance <i>p</i> = 0.002–0.001; <i>d</i> = 1.120–2.140 and <i>p</i> = 0.040–0.001; <i>d</i> = 0.950–1.557, respectively 3D cube and human). In conclusion, beneficial effect on mental rotation tasks involving object-based 3D cubes and human figures was shown in dynamic balance conditions.</p> Conclusions <p>Our findings suggests that physical and cognitive tasks may compete for cognitive resources and signifying potential areas for targeted training and rehabilitation strategies. The outcomes of this study hold potential implications for both cognitive psychology and sports science.</p>