This study aimed to examine the internal structure, score reliability, scoring, and interpretation of the Short Grit Scale (Grit-S; Duckworth & Quinn, 2009) using a sample of engineering students (N = 610) from one large southeastern university located in the United States. Confirmatory factor analysis was used to compare four competing theoretical models: (a) a unidimensional model, (b) a two-factor model, (c) a second-order model, and (d) a bi-factor model. Given that researchers have used Grit-S as a single factor, a unidimensional model was examined. Two-factor and second-order models were considered based upon the work done by Duckworth, Peterson, Matthew, and Kelly (2007), and Duckworth and Quinn (2009). Finally, Reise, Morizot, and Hays (2007) have suggested a bi-factor model be considered when dealing with multidimensional scales given its ability to aid researches about the dimensionality and scoring of instruments consisting of heterogeneous item content. Findings from this study show that Grit-S was best represented by a bi-factor solution. Results indicate that the general grit factor possesses satisfactory score reliability and information, however, the results are not entirely clear or supportive of subscale scoring for either consistency of effort subscale or interest. The implications of these findings and future research are discussed.