Exclusion based on substance use was common in published RCTs for PTSD treatments. Many RCTs used restrictive criteria in terms of SUD diagnosis. Reporting of substance-related outcome findings was uncommon. Most findings reported suggest no disadvantage in PTSD treatment for those with SUD. No clear evidence exclusion criteria relates to PTSD outcome or participant dropout. There is no current evidence that PTSD treatment worsens comorbid SUD.