SUMMARY Background Thought Field Therapy (TFT) is a psychotherapeutic modality often utilised for single-session trauma treatment. It applies sensory stimulation to desensitise painful feelings, and may thus be called a psycho-sensory therapy. Qualitative research on TFT is particularly scarce, and this processual study seeks to fill that void. Research question How do PTSD patients describe their inner experiences before, during and after Thought Field Therapy? Method Three patients diagnosed with PTSD received three weekly sessions of TFT. The first treatment session was filmed, and each participant commented on the recording by describing their awareness of bodily sensations, feelings and thoughts at the time of being recorded. This interview showed in detail the therapist’s sensory interventions and the participants’ inner reactions during one full session. A post-treatment interview sought to identify differences in inner state from pre-treatment. Findings All participants described desensitisation of discomfort in feelings and body, and an inability to concentrate on desensitised matter. Desensitisation was limited to the content of awareness in the phases of sensory interventions, and was described in 22 of a total of 25 interventions. Time in sensory phase was respectively 9, 7 and 8 minutes. The participants described new phenomena from body and feelings during the desensitisation process, and new aspects of meaning. In the post-treatment interview after one week all participants described improvements from their pre-treatment condition. A marked increase in initiative and self-agency post-treatment corresponded positively to a high degree of impaired daily life functions pre-treatment. TFT was here not a single-session therapy, as three sessions of psycho-sensory interventions did not desensitise all painful feelings for any of the participants.