Slang is strongly associated with youths and their everyday-language, but the question is if youths of today also bring the slang with them into the classroom? The aim of this study is to investigate students’ and teachers’ opinions on slang in upper secondary school, their use of slang during their spare time and in school and also to research their attitudes towards slang. The study was carried out through quantitative surveys that were handed out to both students and teachers within upper secondary schools in Norrbotten, Sweden. The result showed that the students and the teachers seem to have a similar views of what slang is and it also showed that the students use slang on their spare time more than the teachers do. The result also indicated that the teachers believe that students use slang sometimes or often in teaching situations, but the students meant that they do it seldom or never in these sort of situations. Both the majority of the students and the majority of the teachers agreed that slang is first and foremost something that is used by youths and that it is used by both boys and girls. Both the teachers and the students had mainly positive attitudes towards the use of slang in different situations. The conclusion that can be drawn from this study is that slang is frequently used in Swedishs upper secondary schools today.