Although the efficacy of exposure is well established in individual cognitive behavioral treatments for posttraumatic stress disorder (PTSD), some clinicians and researchers have expressed concerns regarding the use of in-session disclosure of trauma details through imaginal exposure in group cognitive behavioral therapy (GCBT) for PTSD. Thus, the aim of the present study was to conduct a systematic review of the empirical support for GCBT in the treatment of PTSD and to compare GCBT protocols that encourage the disclosure of trauma details via in-session exposure to GCBT protocols that do not include in-session exposure. Randomized controlled trials that assessed the efficacy of GCBT for PTSD were included in the meta-analysis. A total of 651 participants with PTSD were included in the 12 eligible GCBT treatment conditions (5 conditions included in-group exposure, 7 conditions did not include in-group exposure). The overall pre–post effect size of GCBT for PTSD (ES= 1.13 [SE= 0.22, 95% CI: 0.69 to 1.56, pb.001]). suggests that GCBT is an effective intervention for individuals with PTSD. No significant differences in effect sizes were found between GCBT treatments that included in-group exposure and those that did not. Although the attrition rate was higher in treatments that included exposure in-group, this rate is comparable to attrition rates in individual CBT treatments and pharmacotherapy for PTSD. The results from this meta-analysis suggest that concerns about the potentially negative impact of group exposure may be unwarranted, and support the use of exposure-based GCBT as a promising treatment option for PTSD.