This study examined the cross-cultural construct equivalence of the Structured Interview for Disorders of Extreme Stress (SIDES), an instrument designed to assess symptoms of Disorders of Extreme Stress Not Otherwise Specified (DESNOS). Participants completed the SIDES as a part of an epidemiological survey conducted between 1997 and 1999 among survivors of war or mass violence in Algeria (n = 652), Ethiopia (n = 1,200), and Gaza (n = 585). Findings indicated that the factor structure of the SIDES across samples was not stable; thus construct equivalence was not shown. A multistep interdisciplinary method is proposed to improve the cross-cultural construct validity of a psychiatric concept. This method accommodates universal chronic sequelae of extreme stress and accommodates culture-specific symptoms across a variety of cultures.