ABSTRACT Introduction Gender-affirming phalloplasty involves the construction of a neophallus using one or more flaps, most often a radial forearm free-flap. Although numerous articles have reported on short-term surgical outcomes of phalloplasty, relatively few studies have followed phalloplasty patient prospectively, starting from before surgery, in order to determine how surgery affects sexual function, including orgasm. Objective As part of a prospective, longitudinal study of barriers to and outcomes of masculinizing gender affirming surgery, researchers assessed patients’ sexual function both prior to and after phalloplasty. This represents a sub-analysis of a larger, ongoing research study addressing psychosocial outcomes of gender affirming surgery, including decision regret. Methods The population included in this analysis includes 7 patients who had been followed for at least 6 months after phalloplasty – at which time post-operative sexual function was initially assessed. Six of those patients were also assessed at one year about other psychosexual outcomes of surgery. Both of these assessments involved custom instruments developed for this study. All patients included in this analysis has been assessed at least once prior to surgery. The most recent assessment was used for all patients. Results Of the included participants, five identified as male and 2 as transgender male. All were White and not Hispanic. All patients who had been assessed for sexual function after phalloplasty reported having been able to experience an orgasm after surgery. Five patients stated that they were satisfied or very satisfied with their sexual sensation during the most recent assessment, and 4 stated they were satisfied with their non-erotic (tactile) sensation. However, only one patients reported being satisfied with being able to urinate as they chose. Despite no patients having undergone penile prosthesis insertion at the time of assessment, one patient reported having been able to engage in sexual penetration with a partner. Of the 6 patients who had completed at least one year of follow-up, all reported their masculine self-image was either slightly or much better. Five reported that their nude appearance was slightly or much better, and all reported an increase in comfort in public locker rooms and showers. Conclusions Overall, preliminary longitudinal data suggests that patients who have undergone gender affirming phalloplasty are satisfied with their sexual function, even when they are unsatisfied with their ability to urinate as they choose. These results support previous research showing that orgasmic function can be maintained after gender affirming phalloplasty. Future data will help determine if phalloplasty can improve orgasmic function in the subset of gender affirmation patients who report no history or orgasm prior to surgery. Disclosure Work supported by industry: no.