Research was undertaken into the performances of New Zealand Maori and European children on the Queensland Test of Cognitive Abilities. In addition to studying the comparative performances of the two ethnic groups at six age levels, major psychometric properties of the instrument were investigated. Such data have an important bearing upon the issue of psychological equivalence across ethnic or culture group samples. Seven hundred children (303 Maori and 397 European) aged between eight and a half and fourteen and a half years were tested with the Queensland Test. A small statistically significant ethnic group difference was found favouring the European children. Subsequent analyses indicated that the small difference was of little practical significance. Queensland Test subtest data were also analysed, This indicated that subtest performances were likely to be influenced by subject variables in a manner not necessarily evident in the overall test results. Gender differences in performance on the Pattern Matching Subtest were found and are consistent with other data. Queensland Test reliability, validity and item characteristics were researched for the two ethnic groups. To obtain test-retest reliability estimates and data on criterion related validity longitudinal studies were undertaken with four ethnically mixed class groups Standard 3 to Form 2). The Queensland Test was found to be equally reliable with both ethnic groups although the levels of reliability obtained were not considered entirely satisfactory. Validity data indicated that the same general intelligence construct could be employed in the interpretation of Queensland Test results with both European and Maori subjects. Content validity issues were considered and it was argued that in terms of both test content and measurement procedures the Queensland Test should provide an equally valid measure of general intelligence with both groups. The criterion related validity coefficients were of approximately the same order for each ethnic group although doubts were expressed about the adequacy of the criteria. Construct validity was investigated by considering the relationship of test performance to age and through factor analytic evidence. The analyses supported the view that the Queensland Test was primarily a measure of the same underlying construct within each ethnic group. In terms of prevailing psychological theories on human intelligence this construct was interpreted as being of a general intelligence nature. Comparative data on item characteristics did not indicate any marked ethnic group differences. More apparent was the need to restructure particular subtests where items failed to discriminate adequately within both ethnic groups. It was concluded that the weight of evidence was in favour of the psychological equivalence of this ability measure with Maori and European children. Data for combined ethnic group samples have been reported, Pooled data were employed in some factor analyses and these supported a general intelligence interpretation of Queensland Test results. Preliminary norms were also derived from combined ethnic group data. Findings are discussed in relation to the concept of intelligence and its cross-cultural measurement, other Queensland Test research and recent cross-cultural studies on cognitive abilities in New Zealand.