Introduction: Genital gender affirming surgery (gGAS) is usually the final stage in the medical transition for transgender men and consists of creating a neophallus and neo-scrotum, with or without urethral lengthening(UL). To reduce the complication risks of UL, a mandatory colpectomy is performed prior to UL. Colpectomy is considered a complex surgery, which may lead to various perioperative complications. There are few long-term complications reported. Aim: To describe the clinical presentation and management of 3 consecutive transgender men presenting with a perineal cyst following gGAS. Methods: After obtaining informed consent all clinical data was collected, including medical history, current symptoms, imaging, as well as surgery and histological outcomes. Furthermore, a literature search was performed. Main outcome measure: To hypothesize the aetiology of the perineal cyst based on current published literature. Results: Three otherwise healthy transgender men, ages 26–46 with a similar medical history, presented with a perineal cyst several months or years following colpectomy and gGAS with UL. All patients underwent surgery to remove the cyst. Several theories regarding aetiology of this perineal cyst are discussed in this report. Conclusion: There remain several gaps in our knowledge regarding the aetiology and management of this perineal cyst. Therefore, further research is necessary. Asseler JD, Ronkes BL, Groenman FA, et al. Perineal Cyst in Transgender Men: A Rare Complication Following Gender Affirming Surgery – A Case Series and Literature Overview. J Sex Med 2021;XX:XXX–XXX.