Purpose <p>This study aimed to report on three cases of transgender men who continued testosterone therapy throughout controlled ovarian hyperstimulation for fertility preservation.</p> Methods <p>This was a retrospective case series of three transgender men who presented for oocyte cryopreservation at a university-affiliated fertility clinic and continued gender-affirming testosterone therapy up until or during the controlled ovarian hyperstimulation protocol. The primary outcomes were the number of oocytes retrieved, the number of mature oocytes retrieved, and the total gonadotrophin dose required during stimulation.</p> Results <p>The average age of patients in this series was 29.5&#xa0;years, with an average BMI of 31&#xa0;kg/m². Mean serum testosterone prior to starting stimulation was 359&#xa0;ng/dL. The average AMH and AFC levels were 1.2&#xa0;ng/ml and 12 follicles, respectively, and the mean number of mature oocytes vitrified was 16. One patient fertilized seven mature oocytes and has an ongoing pregnancy following a single blastocyst embryo transfer.</p> Conclusions <p>This is the largest case series of patients who continued testosterone during ovarian stimulation, with the widest range of testosterone dosing reported, and the first report of a self-carried pregnancy after COS on testosterone. While there is no long-term data as yet, these early findings are reassuring for patients and indicate that proceeding with a stimulation cycle without a testosterone washout period, or continuing testosterone during the cycle, may be a reasonable option, thereby increasing the accessibility of fertility preservation for gender-diverse and transgender individuals who wish to continue testosterone.</p>