Health care provider comfort with raising patient safety concerns is a critical aspect of safety culture. This survey of resident physicians at six academic medical centers demonstrated that trainees remain reluctant to speak up. Nearly half reported observing a patient safety threat. The majority spoke up about patient safety concerns, but a significant proportion did not. Although unprofessional behavior was more frequently observed, fewer trainees raised concerns about lack of professionalism than about patient safety. Even when respondents perceived the unprofessional behavior as having high potential for adverse patient consequences, they were not as likely to speak up about this compared to a traditional patient safety threat such as inadequate hand hygiene. The authors recommend specifically measuring tolerance for unprofessional behaviors as a part of safety culture assessment.