Ehlers and Clark's (2000) cognitive model of posttraumatic stress disorder (PTSD) highlights the importance of negative appraisals in maintaining posttraumatic stress. Recent research suggests that alienation appraisals, defined as feeling disconnected from the self and others, mediate the association between traumatic experiences and subsequent PTSD symptoms. To our knowledge, no systematic review has yet explored the relation between alienation appraisals and PTSD symptoms in trauma-exposed adults, despite the important clinical implications posed by this association. A systematic search of the SCOPUS, Web of Science, PsycInfo, MEDLINE, CINAHL Plus, and PILOTS databases resulted in 470 studies, nine of which met full inclusion criteria. Studies were quality-assessed for risk of bias using the Quality Assessment Tool for Studies with Diverse Designs (QATSDD) quality assessment tool. A random-effects meta-analysis for the association between alienation appraisals and PTSD symptoms showed a large total effect size, r = .57, 95% CI [.46, .66], z = 8.41, p < .001. This large effect suggests that as alienation appraisals increase, PTSD symptoms increase. Although a strong positive association was found between alienation and PTSD symptoms, the mechanism of this association remains unclear. Limitations of the research included significant heterogeneity across studies and the fact that data were correlational. Future research to explore why alienation appraisals are significant in posttraumatic stress may further help to inform therapeutic approaches to targeting alienation appraisals in trauma survivors. Recommendations are made for the clinical assessment of alienation appraisals when exploring the impact of the traumatic experience on the survivor. Exposure to traumatic events is common; however, most people who witness or experience traumatic events do not develop posttraumatic stress disorder (PTSD; Schnurr, Friedman, & Bernardy, 2002). A large-scale survey of 2,953 adults in the United States found that although 89.7% of the sample had been exposed to a traumatic event, only 8.3% of the sample met the diagnostic criteria for PTSD per the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; Kilpatrick et al., 2013).