['Women have poorer outcomes after vascular surgery as compared to men as shown by studies recently. Frailty is also an independent risk factor for postoperative morbidity and mortality. This study examines the interplay of gender and frailty on outcomes after infrainguinal vascular procedures.', 'The American College of Surgeons National Surgical Quality Improvement Program database was used to identify all patients who underwent infrainguinal vascular procedures from 2005-2012. Frailty was measured using a modified frailty index (mFI; derived from the Canadian Study of Health and Aging). Univariate and multivariate analysis were performed to investigate the association of preoperative frailty and gender, on postoperative outcomes.', 'Of 24,645 patients (92% open, 8% endovascular), there were 533 deaths (2.2%) and 6198 (25.1%) major complications within 30 d postoperatively. Women were more frail (mean mFI = 0.269) than men (mean mFI = 0.259; P < 0.001). Women and frail patients (mFI>0.25) were more likely to have a major morbidity (P < 0.001) or mortality (P < 0.001) with the highest risk in frail women. On multivariate logistic regression analysis, female gender and increasing mFI were independently significantly associated with mortality (P < 0.05) as well as major complications. The interaction of gender and frailty in multivariate analysis showed the highest adjusted 30-d mortality and morbidity in frail females at 2.8% and 30.1%, respectively and that was significantly higher (P < 0.001) than nonfrail males, nonfrail females and frail males.'] Do gender and frailty predict poor outcomes in infrainguinal vascular surgery?