The investigators will investigate internet delivered prolonged exposure delivered as a ten-week treatment comprising of six modules (psychoeducation/rational, in vivo exposure, imaginal exposure, common problems during exposure, hot spots and relapse prevention). The feasibility and acceptability and preliminary effects of treatment- and assessment procedures will be evaluated using a within-group design with repeated measurements and qualitative interviews. Recruitment is designed to be broadly inclusive with minimal exclusion criteria. Patients will be recruited from a psychiatric clinic specialized in PTSD in Stockholm, Sweden and by advertisements in newspapers and social media.