The effects of repeated freezing and thawing on certain properties of early gestation amniotic fluid were studied. Six amniotic fluids from 15− to 17-week gestations were investigated. Total protein determinations revealed that there was no significant loss of total protein with rapid freezing and thawing up to 10 times in the space of a few days. Immunoelectrophoresis revealed that the antigenic properties of the amniotic fluid, as ascertained by counting the number of precipitin bands, were unaltered by the repeated freezing and thawing.