"Grit" is a stable and measurable trait. It refers to the individual's ability to maintain efforts and interest in projects that take time to complete and are useful in educational contexts. In this study we investigated the validity of a short version of the Grit |International Assessment Scale, Portuguese Version (EAGrit-LP) based on the internal structure and invariance. A total of 1402 students from Brazil (53.2%) and Portugal (46.8%) participated in the survey. The students answered online the EAGrit-LP and the sociodemographic questionnaire. Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were used to reduce the EAGrit-LP from 12 to 8 items, with two factors explaining 55.7% variance and replicating the theoretical structure, with excellent fit indices. Invariance analysis showed no differences in the responses of male and female participants. The results demonstrate that the short version of the instrument presents evidence of internal structure validity and invariance in connection with genders.