Oxidative stress (OS) has been suggested to be involved in the pathogenesis of fertility reduction in aged patient. Silent Information Regulator 1 (SIRT1) is involved in antioxidant defense and also plays a role in regulation ovarian function. The purpose of this study was to evaluate SIRT1 and OS markers in follicular fluid (FF) and granulosa cells (GCs) for aged patient undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).This single-center prospective cohort study was performed from May 2020 to October 2021, including 92 patients undergoing IVF/ICSI at authors' institute. The patients were grouped by age, including group A (< 35 year, n=28, age range 24-29), group B (35-40 year, n=33, age range 35-40), and group C (> 40 year, n=31, age range 41-47). The outcomes included in vitro fertilization and embryo transfer (IVF-ET) results, OS markers and SIRT1 levels.Women in group B and group C had a significantly lower estradiol (E2) in the trigger day, retrieved oocytes, mature oocytes, two pronuclei (2PN) and Day3 available embryos than group A. Women in group C had a significantly lower implantation rate and clinical pregnancy rate than group A. The superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and SIRT1 levels were lower in FF of the group B and group C, whereas the malondialdehyde (MDA) level was higher than that in the group A. Moreover Moreover, the MDA levels were correlated negatively with SIRT1 (r = -0.422, P=0.001),while the SOD and GSH-Px was positively correlated with SIRT1 (r = 0.409, P=0.001 and r = 0.526, P=0.001).The oxidative stress may be related to the decrease of SIRT1 in aged patients undergoing IVF-ET.Copyright © 2022. Published by Elsevier Masson SAS.