Background: The purpose of this study was to evaluate the effect of needle type on pain and bleeding during oocyte pick-up (OPU). Methods: From May through November 2013, patients undergoing OPU from a single follicle without any analgesic treatment were including this study. Eligible patients (n=75) were randomized 1:1 to undergo the procedure with either a reduced needle (17 gauge body, 20 gauge tip; RN group) or a standard needle (19 gauge; SN group). Overall pain was assessed by patients using a visual analogue scale (VAS), and vaginal bleeding after the procedure was recorded. Fisher exact, t-test or Wilcoxon test were used, and p<0.05 was considered to be statistically significant. Results: The percentage of mature oocytes was 86.5% in the RN group and 91.7% in the SN group. Pain during OPU was significantly lower in the RN group than in the SN group (mean VAS score±SD: 3.2±2.0 cm vs. 4.9±2.2 cm, p<0.01; mean±SD). The frequency of bleeding in the RN group was also significantly lower than that in the SN group (26.3% vs. 48.6%; p<0.05). No significant differences were found between the two groups with regard to fertilization and pregnancy rates. Conclusion: The newly designed needle significantly reduced pain and vaginal bleeding associated with single-follicle OPU in patients receiving no analgesic treatment, in comparison with a standard needle. The RN had no adverse effect on the quality of retrieved oocytes.