Abstract Background: Internalized stigma can have numerous negative effects on the well-being and employment of people with mental illness. Brief, valid, and reliable measures are needed to get a better understanding of self-stigmatization. The aim of this study is to translate the brief version of the Internalized Stigma of Mental Illness (ISMI-10) scale into a Dutch version and to assess the reliability and validity of this Dutch version in a sample of employees with mental illness. Methods: The ISMI-10 was translated into Dutch using the forward-backward translation procedure. The sample consisted of 161 employees with mental illness. Internal consistency was evaluated and the retest reliability was tested with 68 respondents. The construct validity was evaluated by testing convergent and divergent validity. Results: The Dutch ISMI-10 showed good internal consistency (α = 0.83) and good test-retest reliability (r = 0.73). The Dutch ISMI-10 demonstrated excellent convergent validity; high correlations were found between the Dutch ISMI-10 and hope (r = -0.54), anxiety and depression (r = 0.59), self-esteem (r = -0.56), and empowerment (r = − 0.59). Acceptable divergent validity was indicated; small correlations were found between the Dutch ISMI-10 and the physical functioning subscale (r = -0.27) and the role limitation due to physical problems subscale (r = -0.21), and medium correlations were found between the Dutch ISMI-10 and the general health subscale (r = -0.36). Conclusion: The Dutch ISMI-10 demonstrated adequate psychometric properties for assessing internalized stigma and can be used by researchers in Dutch speaking countries to get a better understanding of self-stigmatization among people with mental illness.