To assess the reliability and validity of measuring receptive anal intercourse (RAI) sensation and associated satisfaction and bother.Between July 2022 and January 2023, we conducted a survey on sensations during RAI among people with prostates (ie, cisgender men and transgender women). The survey content was developed based on our previous qualitative study. We assessed internal reliability and consistency through time. Sensations experienced during RAI were correlated with health-related quality-of-life measures to ensure construct validity.The final index contained four scales: pleasure (four items), pain (seven items), urinary (four items), and bowel (four items). Overall, 1084 individuals filled out the questionnaire. The internal consistency for all subscales was at or above 0.79. Scores tended to be stable across time with all test-retest coefficients at or above 0.72. Pleasure scores were inversely correlated with pain scores (r = -0.46). Pleasure was positively correlated with erections (r = 0.36) and orgasms (r = 0.44) during RAI, and sexual satisfaction (r = 0.39). Notable positive correlations for pain scores were with bowel scores (r = 0.49), internalized homophobia (r = 0.35), and prostatitis symptoms (r = 0.37). Urinary scores were moderately associated with IPSS scores (r = 0.22). Bowel scores were positively correlated with GI symptoms (r = 0.24), mental health symptoms (r = 0.28), and chronic prostatitis symptoms (r = 0.29).The results of the current study provide evidence that the Anorectal Sexual Function Index is both reliable and valid. The Anorectal Sexual Function Index may be a particularly useful health-related quality-of-life measure to assess outcomes regarding a host of urologic issues that may affect RAI.