Introduction: The Hypersexual Disorder Screening Inventory (HDSI) was developed by the American Psychiatric Association for clinical screening of hypersexual disorder (HD). Aims: To examine the distribution of the proposed diagnostic entity HD according to the HDSI in a sample of men and women seeking help for problematic hypersexuality and evaluate some psychometric properties. Methods: Data on sociodemographics, the HDSI, the Sexual Compulsivity Scale (SCS), and the Cognitive and Behavioral Outcomes of Sexual Behavior were collected online from 16 women and 64 men who self-identified as hypersexual. Respondents were recruited by advertisements offering psychological treatment for hypersexual behavior. Main Outcome Measures: The HDSI, covering the proposed criteria for HD. Results: Of the entire sample, 50% fulfilled the criteria for HD. Compared with men, women scored higher on the HDSI, engaged more often in risky sexual behavior, and worried more about physical injuries and pain. Men primarily used pornography, whereas women had sexual encounters. The HD group reported a larger number of sexual specifiers, higher scores on the SCS, more negative effects of sexual behavior, and more concerns about consequences compared with the non-HD group. Sociodemographics had no influence on HD. The HDSI's core diagnostic criteria showed high internal reliability for men (a = 0.80) and women (a = 0.81). A moderate correlation between the HDSI and the SCS was found (0.51). The vast majority of the entire sample (76 of 80, 95%) fulfilled the criteria for sexual compulsivity according to the SCS. Conclusion: The HDSI could be used as a screening tool for HD, although further explorations of the empirical implications regarding criteria are needed, as are refinements of cutoff scores and specific sexual behaviors. Hypersexual problematic behavior causes distress and impairment and, although not included in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, HD should be endorsed as a diagnosis to develop evidence-based treatment and future studies on its etiology. Copyright (C) 2017, The Authors. Published by Elsevier Inc. on behalf of the International Society for Sexual Medicine. This is an open access article under the CC BY-NC-ND license.