The aim of the present study is to examine the relationships among achievement motivation orientations and academic achievement and interest and whether achievement goals mediate these relationships. A sample of 503 students aged 14-16 years from 8 secondary schools in two Australia cities responded to a questionnaire package, comprising measures of individual-oriented achievement motivation (IOAM), social-oriented achievement motivation (SOAM), achievement goals, and academic interest. Results of the study showed IOAM and SOAM correlated positively. Students endorsed higher levels of IOAM than SOAM. IOAM correlated positively with a mastery-approach goal whereas SOAM correlated positively with mastery-approach, performance-approach, and performance-avoidance goals. Performance-approach and performance-avoidance goals mediated the relationship between SOAM and academic achievement. Mastery-approach goals mediated the relationship between IOAM and SOAM and academic interest.