Introduction: Studies about sexual functioning in trans persons have mainly focused on sexual functioning after genital gender-affirming surgery, have had small sample sizes, and have not explored the broad range of possible sexual dysfunctions. Measuring sexual functioning in trans persons during transitioning is important to determine the kind of care trans persons may need in order to regain their sexual health. Aim: The first aim of the present study was to explore the prevalence of sexual function disturbances and dysfunctions (with distress) in trans women and trans men 4 to 6 years after initial clinical entry. The second aim was to compare the prevalence of sexual dysfunctions among the various treatment trajectories and between trans persons with or without further genital treatment intentions. Methods: An online follow-up questionnaire was filled out by 518 trans persons (307 identifying predominantly feminine, 211 identifying predominantly masculine) as a part of the European Network for the Investigation of Gender Incongruence initiative. All participants had their initial clinical appointments in gender clinics in Ghent, Amsterdam, or Hamburg. Main Outcome Measure: The main outcome measures were the prevalence of sexual dysfunctions and medical treatment data, measured via self-report items. Results: The most frequent sexual dysfunctions experienced by trans women and trans men were difficulties initiating and seeking sexual contact (26% and 32%, respectively) and difficulties achieving an orgasm (29% and 15%, respectively). Compared with trans women after hormone treatment and non-genital surgery, trans women after vaginoplasty less often experienced arousal difficulties, sexual aversion, and low sexual desire. Compared with trans men without medical treatment, trans men after a phalloplasty experienced sexual aversion and low sexual desire less often. No significant differences were found between participants with or without further genital treatment intentions. Clinical implications: Clinicians should consider sexual counseling after medical treatments, paying particular attention to potential social and psychological barriers to the sexual health of their patients. Strengths & Limitations: This study included all trans persons irrespective of treatment decisions, and focused on a broad range of potential sexual difficulties taking the distress criteria into account. Limitations include the cross-sectional design, the limited power for the comparison of treatment groups and the absence of validated questionnaires about sexual functioning for transgender persons. Conclusion: Sexual dysfunctions among trans men and women were very common among the various treatment groups and were unrelated to intentions to have further genital treatment. Although medical treatment may be helpful or even essential to developing good sexual health, a significant group of trans persons experienced sexual dysfunctions after genital surgery. Kerckhof ME, Kreukels BPC, Nieder TO, et al. Prevalence of Sexual Dysfunctions in Transgender Persons: Results from the ENIGI Follow-Up Study. J Sex Med 2019; 16:2018–2019.