Advertising as a discourse type is a powerful ideological apparatus for the reproduction of social and gender identities. In advertising, gender-specific advertisements are often created to address men and women separately. This study sets out to show how the discursive practices of two sets of gender-specific advertisements reinforce sexist assumptions by constructing gender identities based on stereotypical assumptions about men and women. The two sets of ads are closely analysed within a critical discourse analysis approach which draws upon Halliday's systemic-functional framework. Results of the analysis show that advertisers use different discursive practices to construct reading positions for men and women. By conducting a detailed analysis of the discursive practices of the ads, the underlying gender ideology which gives rise to them is denaturalised.