During the three last years, the authors carried out cytogenetic studies of couples with spontaneous abortions, and of spontaneously aborted foetuses. Among 99 couples studied, 9 abnormal karyotypes were detected. In two cases, maternal balanced translocation appears obviously responsible. Concerning aborted foetuses on 46 karyotyped specimens, 13 are found to bear chromosome anomalies. The authors consider the value of cytogenetic studies when repeated spontaneous abortions occur.