HIV/AIDS programmes in schools ultimately intend to decrease high risk sexual behaviour. One factor facilitating this outcome is a strong health promoting environment in the school. This paper reports a study surveying the health promoting environments supporting HIV/AIDS education in Namibian senior secondary schools. It develops a two-dimensional model for classifying the strength of a school's health promoting environment. The findings show that schools have different strengths of health promoting environments linked more to their size than to a rural or urban location. The strength of a school's health promoting environment is closely related to learners' active involvement in HIV/AIDS education activities.