The objective of this study was to culturally adapt and validate a scale to measure HIV-related felt stigma in a group of People living with HIV/AIDS (PLWHA) in Puerto Rico. The researchers conducted a two-phase cross-sectional study with 216 participants (60, first phase; 156, second phase). The first phase consisted of the cultural adaptation of the scale; the second evaluated its psychometric properties. After conducting a factor analysis, a 17-item scale, the HIV Felt-Stigma Scale (HFSS), resulted. Participants completed the Puerto Rico Comprehensive Center for the Study of Health Disparities Socio-demographic Questionnaire, the HFSS, the Beck Depression Inventory-II, and the Sexual Abuse dimension of the History of Abuse Questionnaire; the case managers completed the Case Manager Stigma Guide with subjects. The HFSS measures four dimensions: personalized stigma, disclosure concerns, negative self-image, and concern with public attitudes. The alpha and Pearson correlation coefficients (0.91 and 0.68, respectively) indicated satisfactory validity and reliability; the scale suggested adequate convergent validity. The HFSS is a culturally sensitive instrument that fills the existing gap in the measurement of felt stigma in Spanish-speaking PLWHA.