The objective of this study was to determine the clinical pregnancy rate with 2 inseminations compared to a single intrauterine insemination (IUI) in a given cycle using frozen-thawed donor sperm. This was a retrospective study at a university practice; patients were women using donor sperm. We conducted a comparison of single IUI, intracervical insemination (ICI) followed by an IUI on the next day, and double IUI (2 consecutive days); clinical pregnancy rate was the main outcome measure. The cycle-specific and total pregnancy rates were not significantly different between the 3 protocol groups (306 cycles). The average pregnancy rate over 3 cycles was 10.2% for IUI, 15.3% for ICI/IUI, and 13.7% for IUI/IUI (P = .47). After controlling for repeated measures per subject and age, gravidity, and use of Clomid, there was no significant difference between protocols. The ICI/IUI (odds ratio [OR] = 1.70; 95% confidence interval [CI], 0.83-3.51) and IUI/IUI (OR = 1.5; 95% CI, 0.52-4.33) protocols appeared more likely to result in a clinical pregnancy than the single IUI protocol. Current information on the optimal number of inseminations per cycle using donor sperm is limited. Our large study using 3 protocols found an increase in pregnancy rate with the addition of either an ICI or IUI to a single IUI protocol in a natural or Clomid cycle but did not meet statistical significance. Additional prospective studies are needed to better counsel patients using donor sperm.