<p>This article presents the results of the development and validation of a novel First-Generation University Students Scale (FGUS Scale). It represents the first psychometrically tested set of subscales within a multidimensional framework in Latin America, designed to assess the experiences of FGUSs. Scale development and validation are critical to document these experiences, and to provide a foundation for informing future improvements in the educational experiences of non-traditional higher education students, such as FGUSs. An instrumental design was implemented to develop and examine the psychometric properties of the scale. The sample comprised a total of 530 FGUSs. This included a pre-pilot phase (<i>n</i> = 28), with cognitive interviews conducted with six participants. An analytic sample of 502 participants was then used for psychometric validation, which was split for exploratory (EFA; <i>n</i> = 200) and confirmatory (CFA; <i>n</i> = 302) factor analyses. The final version of the scale consists of 25 items organized into theoretically-meaningful subfactors. Adequate validity and reliability were demonstrated in several subfactors, with a more limited performance in others, supporting their internal structure within each domain. The use of purposive, non-probabilistic samples limits the generalizability of the findings. Future research should focus on implementing a stratified sampling to strengthen the scale’s utility and contribute to comparative research on FGUSs across Latin America.</p> Graphical Abstract <p></p>