In this analysis, single-sex and mixed schools are compared in terms of pupils' television viewing habits, the latter factor being considered as an indicator of a pupil's sense of educational responsibilities. It was hypothesized that the presumably lower levels of television watching among girls attending single-sex schools could be explained by school climate factors pertaining to adolescent subculture values and/or to the pedagogic approaches of a predominantly female staff. Use was made of data from 68 academic-type secondary schools in Flanders (Belgium). Of these schools, 25 were mixed and 43 were single-sex (21 girls', and 22 boys' schools). Respondents were third-year pupils: 3370 girls and 3057 boys, aged 14 and 15 years. A multilevel analysis (HLM) was performed controlling for parental socio-economic status, curriculum enrolment, school residency and school mean SES. The results mainly indicate that the differential effect of single-sex and coeducational schools on girls' TV watching habits may be partially accounted for by factors associated with pedagogic approaches by the predominantly female staff in girls' schools, but not at all by norms related to the adolescent subculture.