Social cognitive career theory (SCCT) and the theories of reasoned action and planned behaviour (TRAPB) have both guided studies seeking to explain students' intentions and decisions related to future science engagement. The purpose of this study was to simultaneously validate measures for these two social psychological models and closely examine these constructs and their associations. Students were sampled in two groups, across grades 5 through 10, from rural schools in the United States (N = 538). Each group was administered two sets of measures, and each set of measures was associated with a theoretical model, and included corresponding sub-scales suitable for self-report. Respondents also supplied information about a common set of predictor variables based on a review of the literature. Structural equation modelling was used to examine the constructs more closely. Results from confirmatory factor analysis were generally consistent with the theoretical structures. Multiple indicators multiple causes (MIMIC) models were generated to compare SCCT and TRAPB, including associations between factors and variables. Associations between common predictor variables like race and gender differed between the MIMIC models. Frequency of talk with family members, perceived science ability, gender, and race were all significantly associated with multiple factors in both the SCCT- and TRAPB-aligned models.