Self-stigma refers to the internalized stigma that individuals may have toward themselves as a result of their minority status. Not only can self-stigma dampen the mental health of individuals, it can deter them from seeking professional help lest disclosing their minority status lead to being shunned by service providers. No unified instrument has been developed to measure consistently self-stigma that could be applied to different concealable minority groups. The present study presented findings based on 4 studies on the development and validation of the Self-Stigma Scale, conducted in Hong Kong with community samples of mental health consumers, recent immigrants from Mainland China, and sexual minorities. Upon a series of validation procedures, a 9-item Self-Stigma Scale–Short Form was developed. Initial support on its reliability and construct validity (convergent and criterion validities) were found among 3 stigmatized groups. Utility of this unified measure was to establish an empirical basis upon which self-stigma of different concealable minority groups could be assessed under the same dimensions. Health-care professionals could make use of this short scale to assess potential self-stigmatization among concealable minorities, which may hamper their treatment process as well as their overall well-being.