Objective: The purpose of this study is to characterize illegal questions as defined by federal law and to assess their impact on applicants’ rank lists across four surgical specialties. Design: A survey was developed and sent to surgical specialty residency applicants. The survey asked demographics, the frequency of questions about age, gender, religion, sexual orientation, family status and impact on final rank list. Applicants were asked to respond anonymously based on their experience at all institutions at which they interviewed during the interview cycle. Results were compared by applicant specialty and gender. Setting: A large university-affiliated academic medical center Participants: Survey was administered to 3854 applicants (comprising between 28.9% and 41.2% of applicants nationwide) to general surgery, orthopaedic surgery, urology, and otolaryngology residency programs at a single institution during the 2018 and 2019 cycles. A total of 1066 applicants completed the survey. Results: A total of 789 (74.0%) of applicants reported being asked at least one illegal question during the interview process at any institution. Applicants to orthopaedic surgery programs were most likely to be asked illegal question (n = 315, 81.6%), and general surgery applicants were least likely to be asked illegal questions (n = 324, 66.8%, p < 0.001). Females were more likely than males to be asked about gender (n = 99, 26.3% vs. n = 18, 2.6%, p < 0.001) and plans for pregnancy (n = 78, 20.8% vs. n = 78, 11.4%, p < 0.001). 152 (19.4%). Applicants reported that being asked an illegal question lowered a program on their rank list. Female applicants were more likely to lower a program on their rank list as a result of an illegal question (n = 102, 35.4% vs. n = 50, 10.1%, p < 0.001). Conclusions: Illegal questions in surgical specialty residency interviews are common, vary by specialty and applicant gender, and lower programs on applicants’ rank lists. This data should serve to inform larger and more inclusive studies in the future. Programs should focus on educating interviewers on illegal topics in an effort to minimize illegal topics that may alienate applicants and contribute to workplace discrimination.