Objective: To examine the psychometric properties of the Frontal Systems Behavior Scale (FrSBe) in a HIV-positive sample using modern Rasch-based methodology. We examined construct validity via dimensionality analysis, item-level functioning, and the extent to which items appropriately measure the level of dysfunction observed in the sample. Method: Participants included 110 HIV-positive (Age: M = 44.96, SD = 9.62; 63% male) and 59 HIV-negative (Age: M = 46.25, SD = 13.29; 51% male) adults. Polytomous items were analyzed in dichotomous format (i.e., presence versus absence of symptoms) due to a lack of variability in responses. Unidimensionality of FrSBe subscales (Apathy, Disinhibition, Executive Dysfunction) was tested and each subscale underwent Rasch analysis. Results: A non-invariant relationship was observed on multi-group CFA (RMSEA = .042, CFI = .882, TLI = .878) and four FrSBe items exhibited differential item functioning (DIF) between participant groups. Within HIV participants, there was moderate support for a unidimensional structure of Apathy (RMSEA = .070, CFI = .919, TLI = .901) and Disinhibition (RMSEA = .066, CFI = .848, TLI = .821) subscales. Rasch analysis of the HIV group revealed that the Apathy and Disinhibition subscales exhibited a spread of items that are well-suited for the range of functioning observed in the sample. Conclusion: The Apathy and Disinhibition subscales may be most valid to use with HIV patients, but further validation with other measures of these constructs is warranted. Within these two subscales, FrSBe items appear to assess the level of dysfunction observed in the HIV sample and capture a wide range of functioning.