This study examined how Finnish primary school students perceive teachers' roles and responsibilities, their own learning and participation, and the social climate during co-taught lessons. Data were collected through a web-based questionnaire among primary school students (N = 242) from grades four to six from Finnish schools where Swedish is the medium of instruction and co-teaching has been initiated. Students with and without special educational needs participated in the study. Students without special educational needs were more positive to co-teaching the more co-taught lessons they received per week, while students with special educational needs were most positive when they received four to five lessons weekly. Students also perceived that mostly the general education teacher is responsible for lesson planning and instruction but that both teachers contribute to the students' learning. In earlier research, the students' perceptions have seldom been in focus and there is an obvious need for more research on students' perspectives to develop and realise co-teaching as a teaching approach that promotes learning and participation for all students in a general classroom.