Many researchers have found differences in the ways in which boys and girls use computers, but there has been no systematic investigation into what types of electronic textbook are good for girls and which are good for boys. This paper describes an experimental investigation in which 35 units from electronic textbooks on mathematics, history, chemistry, geography and the Estonian language were studied by 33 girls and 21 boys aged between 15 and 16 years of age. The correlation coefficients of the girls' and the boys' post-test scores (with the different characteristics of the electronic textbooks) are presented and discussed. The girls' results were associated more with the characteristics of navigation and design of information than the boys' results. There were also different characteristics of text and self-assessment associated with the girls' and boys' test scores. This paper explains the findings in terms of societal factors and the girls' lower level of computer skills. From the findings recommendations for composing electronic textbooks and attitude formation towards computer-aided learning can be recommended.