This study investigated whether teachers at a New Zealand full primary school considered it important for culture generally, and the cultures of their English Second Language (ESL) learners' specifically, to feature in their teaching of ESL pupils. It also examined how the ESL learners' cultures were represented in their lessons. The subject school's six mainstream teachers and sole ESL teacher were interviewed and observed. It was found that teachers had limited knowledge of the backgrounds of their ESL pupils and faced challenges in developing constructive relationships with the ESL families. All teachers reported being aware of their own culture but appeared not to reflect upon it or objectively compare it with cultures they explored as a class, a key component of intercultural language teaching practices promoted in Ministry of Education-endorsed materials for mainstream education of ESL students. New Zealand cultures were dominant as the everyday 'classroom culture'. Explicit teaching of the classroom culture was infrequent, but some elements were made noticeable through more implicit means. Cultures regularly featured as topic studies, however the intentional incorporation of the ESL learners' cultures was infrequent, and most often occurred non-purposefully. It was not clear that teachers recognised school-wide benefits of involving ESL learners' home cultures. Lave and Wenger's (1991) communities of practice model interpreted the findings and indicated current practices might affect the ESL learners' legitimacy as a member of the classroom community of practice and affect their access to the community's resources, its more expert members and its practices. However, it is likely that this is a result of the teachers having limited knowledge of intercultural teaching principles and associated practices, and the belief, of most, that culture is a separate topic, warranting is own allocation of time and other resources, but needing to be sacrificed in order to meet the other challenges of a full curriculum and busy classroom.