Males are often found to outperform females in tests of mathematics achievement and it has been proposed that this may in part be explained by differences in cognitive style. This study investigated the relation between Wholistic-Analytic and Verbal-Imagery cognitive style, gender and mathematics achievement in a sample of 190 Australian primary school students aged between 8 and 11 years. It was hypothesised that males would outperform females in mathematics achievement tests, and that gender would interact with cognitive style on mathematics performance. A significant gender/cognitive style interaction was found. Boys with an Analytic/Imagery style achieved significantly higher results than the girls with an Analytic/Imagery style, supporting the contention that certain cognitive styles affect boys and girls mathematics performance differently. Implications of results and strategies for improving mathematics achievement among girls are discussed.