The present research corresponds to a single case study worked from person-centered psycho-therapy, with a client who consults for post-traumatic stress, after a sexual assault. An analysis was carried out from the qualitative approach, reviewing a clinical case in retrospect, describing the process of change and intervention of the therapist according to certain stages of the psychotherapeutic process. The results show important changes, such as a reduction in anxiety, a decrease in suicidal risk, a stabilization of the mood, greater functionality and autonomy. Person-centered psychotherapy was effective for this particular case, the relevance of non-directivity, therapeutic attitudes and confidence in the actualizing tendency is observed. Due to the characteristics of the study, the results are not generalizable, but it opens up possibilities for future research.