Introduction: Getting sick with cancer is a traumatic event for the affected person and can result with various psychological difficulties, and invasive methods of treatment further deepen them. The previously experienced psychological trauma of a close person can influence the response of a person who is currently experiencing trauma, because the far-reaching power of posttraumatic consequences extends through a natural biological barrier far into the next generation (the so called "transgenerational impact of traumatization"). Objective: To assess the impact of transgenerational transmission on the development of PTSD in women with breast cancer. Methods: The sample consisted of 120 women treated at the Oncology Department of University Hospital Center Osijek, included in liaison psychiatric treatment. A detailed clinical examination with a psychiatric interview was used with the application of DSM-IV diagnostic criteria, a specially structured non-standardized questionnaire for the assessment of etiological factors and the Los Angeles Symptom Checklist of PTSD symptoms (LASC) for determining PTSD. Results: No statistical significance was obtained between the presence of a family member with cancer and the average total score on the LASC in women with newly diagnosed breast cancer. Conclusion: Although there was no correlation between the existence of a family member suffering from cancer and the development of PTSD in the test subjects, during psychotherapy procedures we observed the existence of symptoms that did not meet the criteria for establishing a diagnosis of PTSD, but could interfere with the development of various psychological responses. By including cancer patients in psychotherapy procedures, we can prevent the development of more severe psychological responses in the second generation, which due to the genetic influence in the inheritance of the disease, will develop cancer, and the psychological disorder associated with it, and achieve a far reaching effect on strengthening adaptation mechanisms.