The Children's Motivation Analysis Test (CMAT), together with standardised achievement tests in mathematics and reading, was administered to a large sample of Australian elementary school children. Stepwise forward regression analyses were conducted on subsamples of 209 males and 179 females (cases with missing data previously excluded). Several of the CMAT dynamic traits significantly predicted achievement scores. The most useful predictors were conscientiousness (Superego) and family (Home) orientation. These results, based on objective motivation measurement, represent the beginnings of a new approach for research into children's motivation structure.