At our facility, oocyte retrieval had previously been performed with a 20-gauge standard needle that is uniformly thin overall (tSN); but recently, we have instead started using reduced needles, with a 20-gauge tip and 17-gauge body (RN). Until now, there have been comparisons between RN and thick standard needles, but there have been no comparisons between RN and tSN. The purpose of this study was to compare oocyte retrieval outcomes using RN with tSN. Information on oocyte retrieval was extracted from the medical records of 304 cycles performed at our facility from January 2020 to December 2023. The oocyte retrieval outcomes of the two types of needles were compared retrospectively with respect to age, anti-Müllerian hormone (AMH), procedure time, additional sedatives, number of follicles punctured, number of oocytes retrieved, number of oocytes fertilized, oocyte recovery rate, and fertilization rate.When AMH ≥ 1.2 ng/mL, the procedure time was 9.3 ± 3.7 and 12.1 ± 4.6 minutes in the RN and tSN groups, respectively (P < 0.001), and the need for additional sedatives was also significantly different: 54.0% in the RN group and 78.5% in the tSN group (P = 0.002). The oocyte recovery rate was significantly different between the RN and tSN groups at 65.3% and 61.2%, respectively (P = 0.046), and the fertilization rate was significantly different between the RN and tSN groups at 56.8% and 66.8%, respectively (P < 0.001). There were no significant differences by age, AMH, number of follicles punctured, number of oocytes retrieved, or number of oocytes fertilized.Without diminished ovarian reserve, RN reduced procedure time and the need for additional sedatives compared to tSN. In addition, the number of oocytes fertilized per oocyte retrieval remained the same, indicating that oocyte retrieval performance was not affected.