ObjectiveTo understand the situation of off-label use of aspirin among outpatients in Sun Yatsen Memorial Hospital, so as to provide baseline data for developing off-label drug use policy. MethodsA stratified random sampling method was used to collected prescription data of aspirin among outpatients in 2013. The incidence rates between different types of off-label use of aspirin were determined by chi-square test, and the influence factors of off-label drug use were analyzed by logistic regression model. ResultsA total of 5 023 prescriptions with aspirin were collected and analyzed, with incidence rate of off-label use up to 17.7%. The major category of off-label use was no indication (94.38%). The top 3 no indications were recurrent abortion, infertility and systemic lupus erythematosus. Drug specification, gender, age and prescribed department were the risk factors of off-label use. ConclusionAspirin off-label use is common among outpatients in Sun Yat-sen Memorial Hospital in 2013, especially in obstetrics and gynecology department and assisted reproductive center. The results suggest that more clinical studies about aspirin for reproduction are needed to provide more evidence of drug use, so as to ensure the safety of drug use in special populations and avoid potential medical risk.