Studies concerning BDSM sexual practices within the general population often use different criteria to differentiate between those who practice or identify by them vs. those who do not. Yet, using criteria such as BDSM self-identification or measuring the actual frequency of these practices incur in limitations that likely over or underestimate the prevalence of these behaviors, making the interpretation and comparison of the results inaccurate across studies. Therefore, the following study examined the magnitude of difference between using BDSM self-identification vs. BDSM practice frequency as criteria, across conventional and non-conventional sexual behaviors, as well as sexual function in the general population. This study was composed of 3904 Chilean men and women. Sexual function was measured using the International Index of Erectile Function (IIEF) and the Female Sexual Function Index (FSFI). Results revealed differences in the prevalence of BDSM individuals by criteria varying by behavior, whereas correlations between BDSM criteria were positive, yet of low magnitude. The practice frequency criterion yielded a larger prevalence of BDSM practitioners, with higher engagement in BDSM-specific behaviors, greater pleasure derived from these practices, and better sexual function compared to non-BDSM individuals, especially among highly frequent practitioners. Lastly, differences in sexual function dimensions according to BDSM criteria were found more frequently, and by a larger magnitude, through the BDSM practice frequency criterion, especially in women, compared to non-BDSM people. This study findings demonstrate the importance of considering both self-identification and practice frequency criteria in understanding BDSM and its implications for sexual health in future studies.