Purpose. The article presents the results of adaptation and validation of the International Trauma Questionnaire (ITQ) on a Russian sample. The questionnaire measures the symptoms of complex post-traumatic stress disorder (CPTSD), which can develop as a result of exposure to prolonged, repetitive traumatic experiences in the interpersonal sphere. Method. The study was carried out on a non-clinical sample, which included 429 participants who were 18 to 68 years old and who experienced at least one traumatic event in their lives. International Trauma Questionnaire (ITQ), LEC-5 (Life events checklist-5), author’s questionnaire “Emotional abuse”, Symptom Checklist (SCL-90-R) were used in the study. Results. The structure of the questionnaire in the Russian-speaking sample confirmed the two-factor model of complex PTSD, which combines the symptoms of PTSD («Re-experiencing», «Avoidance», «Sense of Threat») and disturbances of Self-organization («Affective Dysregulation», «Negative Self-concept», «Disturbances in Relationships»). Internal consistency of the scale was in the acceptable range. Among those who have experienced at least one traumatic event, 20% met criteria for PTSD (11%) or CPTSD (9%). These data show that respondents with CPTSD have more intense psychopathological symptoms than respondents with PTSD; women show more intense symptoms of CPTSD than men.