The paper presents the results of a clinical-psychopathological and experimental psychological study carried out on 91 women with breast cancer (aged 35—65, mean age 55.8±11.08 years). The sample was divided into two groups, 51 women with a diagnosed posttraumatic stress disorder (PTSD) developed as a result of their illness and 40 stress-resistant women. The author’s semi-structured anamnestic interview was used to study the clinical and socio-psychological characteristics of patients. Methods: Trauma Screening Questionnaire (Brewin et al., 2002), Impact of Event Scale (Tarabrina, 2001), Type of Attitude to the Disease measure (Vasserman et al., 2014), G. Ammon’s Ego Structure Test (Tupitsyn et al., 1998), Mental Health Assessment measure (Bocharov, Tupitsyn, 1999), The Personal Views Survey III- R (Leontiev, Rasskazova, 2006), Experiences in Close Relationships (Kazantseva, 2008). Results: In patients with PTSD, low parameters of resilience, the dominance of maladaptive types of attitude to the disease, and deficient and destructive personality structures (aggression, anxiety, deficient external and internal boundaries of the self, and destructive narcissism and sexuality) were revealed.