BACKGROUND The AUB-HAS2 Cardiovascular Risk Index is a recently published tool for pre-operative cardiovascular evaluation. It is based on six data elements: history of heart disease, symptoms of angina or dyspnea, age ≥ 75 years, hemoglobin < 12 mg/dl, vascular surgery, and emergency surgery. The objective of this study is to study the effect of age and gender on the performance of the AUB-HAS2 Index in pre-operative cardiovascular risk assessment. METHODS The study population consisted of 1,167,414 non-cardiac surgeries registered in the ACS NSQIP database. The population was stratified by age (≥ 40 and < 40 years old) and by gender (men and women). Each patient was given an AUB-HAS2 score of 0, 1, 2, 3, or > 3 based on the number of data elements s/he has. The outcome measure was all-cause mortality, myocardial infarction (MI), or stroke at 30 days after surgery. RESULTS The overall 30-day event rate was higher in patients ≥ 40 years compared to those < 40 years (2.5% vs 0.3%, P < 0.0001) and in men compared to women (2.7% vs 1.8%, P < 0.0001). In both age and gender subgroups, there was a gradual and significant increase in the outcome measure (death, MI, or stroke) as the AUB-HAS2 score increased: from ≤ 0.5% in those with a score of 0 to more than 15% in those with a score > 3 (P < 0.0001). The AUB-HAS2 Index was able to stratify risk in all subgroups into low, intermediate, and high (P < 0.0001). Receiver operating characteristic curves showed the AUB-HAS2 Index has very good discriminatory power in both age (area under the curve (AUC) of 0.81 and 0.78) and gender (AUCs of 0.79 and 0.84) subgroups. CONCLUSIONS This study extends the validation of the newly derived AUB-HAS2 Cardiovascular Risk Index to different age and gender subgroups with very good discriminative power.