The network approach in the eating disorder (ED) field has confirmed important links between EDs and posttraumatic stress disorder (PTSD) symptoms. However, studies including comorbid symptoms are scarce, which limits our understanding of potentially important connections. We hypothesised that anxiety, depression and poor quality of life (QOL) would provide a more complete picture of central, maintaining factors. Network analysis using R was performed in 2178 adult ED patients (91% female) admitted to residential treatment. Assessments included the ED Examination Questionnaire (EDEQ), the Eating Disorders Inventory (EDI-2), the PTSD Checklist for DSM-5 (PTSD clusters (PCL-5)), the Patient Health Questionnaire (PHQ-9), the Spielberger State-Trait Anxiety Scale (STAI), and the ED QOL Scale (EDQOL), which measure symptoms of EDs, PTSD, major depression, state-trait anxiety, and QOL, respectively. EDI-2 ineffectiveness showed the highest centrality (expected influence) followed by EDI-2 interoceptive awareness, STAI state anxiety, EDEQ shape concern, EDQOL psychological subscale, and PTSD cluster D (hyperarousal) symptoms. Eating Disorder Quality of Life psychological and physical-cognitive subscales and PHQ-9 major depressive, STAI state anxiety and PCL-5 PTSD cluster E (negative alterations in mood and cognition) symptoms showed the highest bridge expected influence, suggesting their interactive role in maintaining ED-PTSD comorbidity. This is the first network analysis of the interaction between ED and PTSD symptoms to include the comorbid measures of depression, anxiety, and QOL in a large clinical sample of ED patients. Our results indicate that several symptom clusters are likely to maintain ED-PTSD comorbidity and may be important targets of integrated treatment.