IntroductionThe Stigma Affiliation Scale (ASS) is an instrument to assess affiliation stigma used widely worldwide. This study aims to adapt the ASS to the Indonesian language and to evaluate the psychometric properties of the ASS among family caregivers of people with schizophrenia in Indonesia.MethodsA cross-sectional study was conducted of 94 schizophrenia patients’ family caregivers in communities, i.e., an items analysis, construct validity using the known-group method, and internal consistency reliability.ResultsThe consistency between items and overall scores using Pearson product-moment correlation shows that all the items had Pearson’s coefficient correlation ≥ 0.300, indicating good and acceptable discriminant power. The construct validity using the Mann–Whitney U test comparing the ASS scores between the primary caregivers and other family members of schizophrenic patients showed higher scores in the primary caregivers than the other family members in the three domains (p < 0.0001), indicating excellent construct validity. Cronbach’s alpha was 0.80–0.89 and above 0.90, which indicate good and excellent reliability, respectively.ConclusionThe Indonesian version of ASS shows good psychometric properties among family caregivers of people with schizophrenia in Indonesia.