Balanced chromosome rearrangements have been found at an increased frequency in couples with pregnancy wastage, especially recurrent spontaneous abortions, compared with the general population. In the present study, chromosomal analysis of peripheral blood cells, as one of the routine examinations of patients with repeated reproductive wastage, was performed on both partners of 639 Japanese couples. Among the 639 couples, 32 major chromosomal anomalies (5.0%) and 23 minor chromosomal variants (3.6%) were found. Both partners of one couple had an abnormal karyotype. The 32 major anomalies consisted of 19 reciprocal translocations, 9 Robertsonian translocations, one large inversion, two triple-X females, and one Turner mosaicism. The 23 minor variants included 15 cases of pericentric inversion of chromosome 9. The total number of pregnancies in the 54 couples with chromosomal anomalies was 181, but they resulted in only 18 normal liveborn neonates, indicating a 90.1% abortion rate. The present statistical study indicates that major chromosomal anomalies seem to be involved in repeated reproductive wastage.