Hierarchies through Teaching, Classification and Regulation of Students This paper draws upon an ethnographic research project on 'Difference and Marginalization in School - with Special Reference to Gender and Social Background' that was undertaken during 1996-2001 at three secondary schools in Oslo. While sexuality did not figure initially as a primary concern of the research, it soon became apparent that a number of incidents and situations appropriated and reproduced discourses on sexuality that had marginalizing implications. In this paper I intend to analyse teacher practices linked to institutional relations; teaching, classification practices and regulations of students. I will demonstrate through case studies that teachers contribute in the construction of sexual identities and regulation of sexuality in schools that in effect may enhance gendered hierarchies. I argue that the institutional settings frame teacher practices and affect the ways teachers may 'look at' and interpret incidents with sexual connotation, and authorize and legitimize particular ways of dealing with sexuality.