Background: A broad range of psychopathological sequelae was found in adult survivors of institutional childhood maltreatment (IM). Childhood maltreatment is also associated with lower self–esteem (SE). In previous qualitative research, adult survivors of IM reported feelings of worthlessness and self-doubts, but research on IM and its associations with SE is still scarce. Method: To investigate the emotional facet of SE in 46 adult survivors of IM in foster care settings provided by the City of Vienna we used the Emotional SE subscale of the Multidimensional Self-Esteem Scale (‘Multidimensionale Selbstwertskala’, MSWS) and applied a semi-structured interview with open-ended questions. Qualitative data were analyzed with thematic analysis. Finally, qualitative and quantitative data were merged in a mixed method approach to detect similarities and differences between both assessment modalities. Results: Findings showed a significantly lower emotional SE level (MSWS) in adult survivors compared to a norm sample. Qualitative findings revealed five main themes reporting positive and negative emotions and attitudes towards oneself. Merged data showed a tendency of more positive attitudes and emotions within participants with higher emotional SE levels and more negative attitudes within participants with lower levels. No gender differences were found in both data sets. Conclusions: IM seems to predict lower emotional SE. Observed qualitative aspects of emotional SE seem to concur with symptoms of disturbances in self-organization (DSO) that are typically present in persons suffering from Complex PTSD. Considering emotional SE in future research could facilitate the understanding of the sequelae of complex trauma.