Prenatal Practice Staff Perceptions of Three Substance Use Screening Tools for Pregnant Women Objective: There is a need to identify an acceptable and comprehensive substance use screening tool for pregnant women in the United States. This qualitative study sought to better understand prenatal practice staff perceptions of three existing substance use screening tools for use among pregnant women in an outpatient practice setting. Methods: Eight focus groups with 40 total participants were conducted with clinical and administrative staff of 2 diverse Maryland prenatal practices to determine the acceptability and usability of 3 substance use screening tools (4P's Plus, NIDA-Modified Alcohol, Smoking and Substance Involvement Screening Test, and the Substance Use Risk Profile-Pregnancy scale). The focus groups were digitally recorded, transcribed, coded, and analyzed using thematic analysis. Results: Participant perceptions of screening tools were dependent upon screening tool length, tone, comprehensiveness, subjectivity, time frame of questions, and scoring and clinician instructions. Most participants preferred the 4P's Plus screening tool because it is brief, comprehensive, easy for the patient to understand, and excludes judgmental language and subjective questions. Conclusions: These results provide valuable insight into the specific needs and preferences of prenatal practice staff as it relates to prenatal substance use screening and provides evidence that the 4P's Plus may be a preferred screening tool for standardized use in prenatal care. Send correspondence to Victoria H. Coleman-Cowger, PhD, The Emmes Company, LLC, 401N. Washington Street, Suite 700, Rockville, MD 20850. E-mail: vcolemancowger@emmes.com Received 7 December, 2018 Accepted 18 March, 2019 Funding: Research reported in this publication was supported by the National Institute on Drug Abuse of the National Institutes of Health under Award Number R01DA041328. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the Health Resources and Services Administration. The authors report no conflicts of interest. © 2019 American Society of Addiction Medicine