The history of frozen human semen is reviewed and the clinical devel opments which began in 1964 are given in greater detail. Artificial insemination has become widely accepted and thousands have been performed successfully. 40-45% survival of spermatozoa have been recorded after 10 years of storage. No evidence suggests that storage produces genetic changes. Conservative data show 564 children have been born from frozen semen using approved insemination procedures, 7 abnormal children were born, 50 spontaneous abortions were recorded, and 65 pregnancies had not yet resolved themselves. Periods of preservation ranged from 13 months (Japanese series) to 10 1/4 years (U.S.). Names and addresses of researchers maintaining semen banks are given. Application of the technology to infertility, as "insurance" for men undergoing vasectomy, and as a method for improving genetic characteristics are discussed. Commercial banks with regulated standards and a clarified policy of no guarantee of fertility were endorsed as essential to large-scale application of this technology.