The use of ayahuasca for healing trauma and resolving associated symptoms has gained increasing attention recently. As a result, a surge of trauma survivors has converged on healing centers around the world in pursuit of ayahuasca therapy. Although research into ayahuasca has suggested it is safe and holds great therapeutic potential for mental health disorders, the potential for harm has been highlighted in recent years, particularly around set and setting with inexperienced facilitators and centers exploiting this rapidly growing market. The current study reports on data from a retrospective cross-sectional online survey of ayahuasca users either with or without a self-reported history of post-traumatic stress disorder (PTSD). Data reported here capture the potential risks of ayahuasca use in people with a history of PTSD and how they compare to the reported benefits. Results suggest that while most people find ayahuasca to be helpful (79–97%) and not dangerous (67–76%), people with a history of PTSD were 10% more likely to disclose information about dangerous experiences associated with taking ayahuasca, compared to those with no reported history of PTSD. Qualitative assessments of open-ended responses regarding dangerous experiences included feelings that the facilitators were inexperienced, not having sufficient physical and psychological support, inadequate facilities for purging, overcrowding in ceremonies, lack of follow-up care, and insufficient screening of participants with psychotic disorders who became violent. While most people found the experience to be helpful and healing, people are reporting unfavorable responses to ayahuasca, particularly those with a history of PTSD. Further investigation is necessary to develop best practices that ensure safety for participants with PTSD when seeking ayahuasca therapy.