Background: In England, there are concerns about boys' under-achievement in reading, and girls consistently do better than boys in national reading tests taken by 11-year-olds. At the same time, there have been accusations of bias in the content of the reading tests. Purpose: This article looks at the performance of boys and girls on the 2008 reading test during its development. Sample: In April 2007, 1423 students from a nationally representative sample of 62 primary schools participated in the final pre-test of the key stage 2 reading test, the same test that was taken by the whole cohort in May 2008. Design and methods: The study investigated students' stated enjoyment of the texts they had read, and analysed their performance on the test as a whole and on each item separately. The analyses were conducted for boys and girls separately, and for the two groups split by teacher assessment level. A differential item functioning by gender was conducted and differential omission rates were scrutinised. Results: There were differences between boys' and girls' stated enjoyment of the texts in the test. There were differences in the extent to which boys and girls omitted items in the test, with boys, especially lower achieving boys, more likely to omit items than girls. Nine out of 32 items showed a significant differential functioning and there was some relationship between this and the text type to which the item referred. Conclusions: This investigation suggests that there are differences between boys and girls in their preferences for different genres and in their test-taking strategies. (Contains 4 figures and 7 tables.)