Background: Dynamic balance assessment, which requires a specialized device, is crucial in clinic to evaluate postural control comprehensively. The Nintendo Wii Balance Board (WBB), a portable force platform may be a suitable alternative to the expensive “gold standard”- the laboratory-grade force platform (FP). However, its validity in assessment of dynamic balance is still unclear. The purpose of this study is to demonstrate the validity of the WBB in dynamic balance assessment.Methods: We performed three static and dynamic balance tests, including open eyes single-leg stand, close eyes single-leg stand and Limitation of Stability, on the WBB for 34 healthy participants. Trajectories of center of pressure (COP) were recorded synchronously and used to compute seven characteristics. To quantify the consistency of the two devices, we used intraclass correlation coefficient (ICC) as well as visual evaluation of Bland–Altman plots.Results: The data showed a high consistency between the two devices (ICC = 0.92-0.98) under static and dynamic balance assessments, and the visual evaluation result from Bland–Altman plot was acceptable between device agreement. Moreover, in the dynamic balance task (Limitation of Stability test), the typical ranges of COP-based postural sway distances for healthy adults in medial-lateral and anterior-posterior measured by the WBB were 27.17 ± 3.88 cm and 21.13 ± 2.33 cm, respectively, indicating the validity of the WBB in assessing COP under both static or dynamic balance tasks. Conclusion: With the advantages of portability and low-cost, the valid WBB can facilitate the popularization of quantitative balance evaluation to basic hospitals. Our results provide valuable reference for clinical evaluation of balance ability.