Perioperative patients are at risk of developing stress ulcers (SU), which can cause clinically important bleeding. Stress ulcer prophylaxis (SUP) is widely applied to the patients in Intensive care unit (ICU) as well as the general ward, so it may lead to overmedication. However, there have been no surveys regarding SUP knowledge or prescribing habits.Our study assessed the knowledge, attitudes, and prescribing behavior of the surgeons toward perioperative patients regarding SUP and determined factors associated with low knowledge and high level of prescribing behaviors.We performed a cross-sectional survey using questionnaires, randomly sampling 1266 surgeons on their current SUP practices.Proton pump inhibitors for SUP were used the most (94%); 43% used lansoprazole. Guideline awareness was inconsistent; the most familiar guideline was the National Medical Journal of China, and 46% were unaware of any guidelines. The predictors of low knowledge score regarding SUP in multivariable analysis were the hospital grade (p = 0.000), the type of hospital (p = 0.044), attendance at continuing education programs (p = 0.037), the awareness of clinical practice guidelines (CPGs) for SUP (p = 0.000). Twenty-one percent of physicians were high prescribers. High prescribing behavior was associated with hospital grade(p = 0.000), education level(p = 0.010) and attendance at continuing education programs (p = 0.000).We found that most surgeons used SUP, primarily proton pump inhibitors. However, surgeons knew little about the SUP guidelines, which may lead to insufficient SUP knowledge and overmedication. In addition, hospital grade, the type of hospital and attendance at continuing education programs may also affect the low knowledge of SUP. Hospital grade, education level and attendance at continuing education programs may affect high prescribing behavior.© 2021. The Author(s).