Biology, chemistry and physics might be taught as separate subjects, but sometimes they are taught as combined with one another or with other subjects. Nationally and internationally the concept integrated science teaching lacks a uniform definition. To find out more about how practicing teachers define and perform integrated teaching, interviews were undertaken with five teachers, teaching science in school year 7 to 9 (age 13-16) in the Swedish compulsory school. Two ways of integrating science teaching were found; one combining the science subjects and one combining the science subjects with other school subjects. Results showed differences in the ways of teaching integrated science, in the interpretation of what the teachers meant by science integrating teaching and which obstacles and possibilities they saw. Visions about working with integrated science in the future and how these visions correspond to teacher’s reality is also discussed.