This research reports on a twelve-week experimental study conducted in one upper secondary English as a second language classroom at a school in southern Sweden. In the study in I investigated how the use of the process writing approach affects student writing abilities as well as student and teacher perception of student writing development. By means of an initial interview, I explored the teacher’s theoretical understanding of planning, teaching and assessing according to the process writing approach. In addition, pre- and post-test were conducted for assessing how students perceived their own development in writing ability. In the investigation, twenty students in an English 5 class participated in twelve weeks of teaching based on the process writing approach in which they were assessed on writing assignments both at the beginning and end of the intervention in comparison to control groups from two prior terms that did not receive the intervention. The interview results showed that teacher understanding of the cognitive theories associated with the process approach were implemented in her planning, teaching and assessment. The study concludes with results indicating a significant improvement of learners perception in post-test compared to pre-test. The investigation of how the process writing approach affected the interventions groups writing indicates the methods effectiveness. As such, implementing the process writing approach to teach academic writing in the subject of English in a Swedish context appears to offer learners potential learning opportunity worthy continued investigation.