OBJECTIVE: The goal of this study was to compare the semen parameters of two successive samples obtained within an interval of less than 60 minutes from patients planning to undergo intrauterine insemination (IUI) whose first samples exhibited low semen quality. METHODS: Thirty-two consecutive patients were enrolled in the study. On the day of IUI, the semen analysis of the samples initially presented by all patients met at least two of the following criteria: sperm concentration <5×10(6)/mL, total sperm count <10×10(6), progressive sperm motility (a+b) in the native sample <30%, and total motile sperm count (TMSC) <4×10(6). A successive semen sample was obtained no more than 60 minutes after the first sample. RESULTS: Compared to the first sample, the second exhibited significantly (p<0.05) improved sperm concentration, TMSC, progressive motility, and vitality. Regarding TMSC, the most critical parameter on the day of IUI, 23 patients (71.8%) improved it, while nine (28.2%) displayed poorer outcomes. CONCLUSION: In defined cases, requesting a second successive ejaculate on the day of insemination may result in a high percentage of cases in an improvement of the quality of the sample.