The purpose of this study is to examine the potential multidimensional and hierarchical structure of student's motivational goals and academic self-concept (SC). Specifically, this paper tests the ability of first- and second-order measurement models comprising achievement motivation variables (mastery, performance & social goals) and academic self-concept variables (English and math self-concept) to fit data collected over two years from 1 515 Australian High School students. The study also tests whether the second-order model fits equally well across sex groups. Results of the first-order Confirmatory Factor Analyses (CFA) demonstrate that the motivation items drawn from the General Achievement Goal Orientation Scale (GAGOS), and the self-concept items drawn from the Academic Self Description Questionnaire II (ASDQ II), appropriately measure their target constructs. The higher-order CFA results provided support for an hierarchical representation of goals and self-concept, with goodness-of-fit indices for Time 1 (T1) and Time 2 (T2) ranging from .86 to .92. This model fitted the data equally well for males (with goodness-of-fit indices for T1 and T2 ranging from .83 to .92) and females (with goodness-of-fit indices for T1 and T2 ranging from .85 to .92). Thus, the study provides a measurement framework, which is largely sex-invariant, and within which the interaction of multiple achievement goal orientations and academic self-concept variables may be examined.