Introduction: The Wii Balance Board (WBB) is a commonly used tool for balance assessment, however the inconsistency in the reported validity for the WBB when used for the assessment of healthy young adults needs to be clarified. Aim: To investigate the concurrent validity and reliability of the WBB for balance assessment in healthy young adults. Methods: Thirty-two young adults participated in this study. Their ability to balance was tested while standing on a WBB and a laboratory-grade force platform, under three conditions: feet together with eyes open, feet together with eyes closed and semi-tandem standing with eyes open. They had 10 min resting period between tests. The agreement between the WBB and the laboratory-grade force platform was investigated, and the reliability of the WBB was determined. Results: A poor agreement between the WBB and the laboratory-grade force platform was found for all standing conditions [intraclass correlation coefficient (ICC) = 0.03 to 0.07]. A moderate to high reliability was found for the WBB for balance assessment in healthy young adults (ICC = 0.66 to 0.76). Conclusion: The WBB was found to be a reliable tool for static balance assessment in healthy young adults. However, it had poor validity compared to the laboratory-grade force platform.