An attitude of rejection toward people living with HIV/AIDS (PLWHA) in the clinical setting has a negative effect on their care. Given the importance of assessing the attitude toward PLWHA in medical students and having a reliable and valid instrument for its measurement, the objectives of the article are to test the factorial invariance of the one-factor model proposed for the six-item Attitude Scale for People Living With HIV/AIDS (AS-PLWHA-6) across sexes and to compare the percentage of acceptance toward PLWHA between women and men. The AS-PLWHA-6 was applied to a sample composed of 202 Mexican medical students. A non-probability sampling was used. The data were analyzed using multi-group factor analysis through Maximum Likelihood. The goodness of fit was statistically equivalent between the four models nested in constraints based on the chi-square difference test. In the unconstrained parameter model and in the model with constraints on measurement weights, there was no difference of parameters between both samples. In the model with constraints on all parameters, the data fit was close through AGFI, RMSEA, and χ2/df, whereas the fit was acceptable through the chi-square test, Bollen-Stine bootstrap probability, GFI, CFI, and SRMR. It is concluded that the one-factor model is invariant across sexes, and an attitude of acceptance prevails among students. The use and study of AS-PLWHA-6 in this population is recommended