Abstract
This article reports results of the study that examined constraints on the integration of Sustainability Education in Namibian colleges of education. The sample consisted of sixty-four (64) teacher educators selected from a total of one hundred and seventy-two (172). The findings of the study show that institutional, dispositional and situational constraints affect the cross-curricular integration of Sustainability Education in these colleges. The recommendations support the re-orientation of administration, curriculum and in-service training for teacher educators and administrators in order to support the cross-curricular integration of Sustainability Education in Namibian colleges of education.