The psychometric properties of the paper–pencil and online versions of the Beliefs Toward Mental Illness Scale (BTMI) were examined in two studies with Latina/o individuals. In Study 1, 316 Latina/o participants completed the BTMI in a paper–pencil mode. The original three-factor model was found to be a poor fit model for the sample. Subsequent exploratory and confirmatory factor analyses identified a four-factor model as the best fitting model for the sample. The identified factors were Dangerousness, Social Dysfunction, Incurability, and Embarrassment. In Study 2, the identified best fit model was tested with 280 Latina/o participants who completed the BTMI online. The four-factor model had adequate fit. A series of measurement invariance tests on the fit model supported equal factor loadings, but rejected equivalent intercepts across paper–pencil and online administration methods, though partially equivalent intercepts and residuals were found. Consequently, modality-specific norms are recommended, depending on whether paper–pencil or online venues are utilized for administration.