The purpose of the present study was 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 a hypothesised second-order measurement model 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, and to test whether the model fits equally well across sex groups. Results of first order Confirmatory Factor Analyses (CFA) demonstrate that the combined General Achievement Goal Orientation Scale (GAGOS) and Academic Self Description Questionnaire II (ASDQ II) provide adequate reliability estimates on each scale and validly measure the constructs. Higher order CFA results provided support for an hierarchical representation (with goodness-of-fit indices for Time 1 (T1) and Time 2 (T2) ranging from .86 to .92). The 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 within which the interaction of multiple achievement goal orientations and academic self-concept variables may be examined further.