ABSTRACT: Assess perceptions of prevalence, safety, and screening practices for cigarettes and secondhand smoke exposure (SHSe), marijuana (and synthetic marijuana), electronic nicotine delivery systems (ENDS; eg, e-cigarettes), nicotine-replacement therapy (NRT), and smoking-cessation medications during pregnancy, among primary care physicians (PCPs) providing obstetric care.A web-based, cross-sectional survey was e-mailed to 3750 US physicians (belonging to organizations within the Council of Academic Family Medicine Educational Research Alliance). Several research groups' questions were included in the survey. Only physicians who reported providing "labor and delivery" obstetric care responded to questions related to the study objectives.A total of 1248 physicians (of 3750) responded (33.3%) and 417 reported providing labor and delivery obstetric care. Obstetric providers (N = 417) reported cigarette (54%), marijuana (49%), and ENDS use (24%) by "Some (6% to 25%)" pregnant women, with 37% endorsing that "Very Few (1% to 5%)" pregnant women used ENDS. Providers most often selected that very few pregnant women used NRT (45%), cessation medications (ie, bupropion or varenicline; 37%), and synthetic marijuana (23%). Significant proportions chose "Do not Know" for synthetic marijuana (58%) and ENDS (27%). Over 90% of the sample perceived that use of or exposure to cigarettes (99%), synthetic marijuana (99%), SHS (97%), marijuana (92%), or ENDS (91%) were unsafe during pregnancy, with the exception of NRT (44%). Providers most consistently screened for cigarette (85%) and marijuana use (63%), followed by SHSe in the home (48%), and ENDS (33%) and synthetic marijuana use (28%). Fewer than a quarter (18%) screened consistently for all substances and SHSe. One third (32%) reported laboratory testing for marijuana and 3% reported laboratory testing for smoking status.This sample of PCPs providing obstetric care within academic settings perceived cigarettes, marijuana, and ENDS use to be prevalent and unsafe during pregnancy. Opportunities for increased screening during pregnancy across these substances were apparent.