OBJECTIVE To compare the efficacy of intracervical insemination (ICI), intrauterine insemination (IUI), and a combination of intratubal and intrauterine insemination (ITI/IUI) for donor insemination. METHODS Prospective randomized clinical trial. METHODS The University of Michigan donor insemination program. METHODS Forty-one women undergoing donor insemination with cryopreserved sperm for either isolated male factor or male factor plus ovulatory dysfunction corrected by clomiphene citrate. METHODS Each patient was randomly assigned to receive each of the three insemination techniques in consecutive cycles until pregnancy occurred or the patient dropped from the study. METHODS Cycle fecundity rates were compared using the chi 2 test, and cumulative pregnancy rates (PRs) determined by life table analysis were compared using a log-rank test. RESULTS Cycle fecundity rate was significantly higher for IUI (18.3%) than for ICI (3.9%) or ITI/IUI (7.3%). By life table analysis, the cumulative PR for IUI was significantly higher than for ICI, but the PR for ITI/IUI was not. CONCLUSIONS For donor insemination with cryopreserved sperm, IUI increases cycle fecundity compared with ICI. The addition of ITI to IUI, however, interferes with the apparent beneficial effect of IUI alone.