Eighty-five specimens (56%) of 149 samples of spontaneous fetal abortions grew initially in tissue culture. Sixty were cultivated with only minimal growth and were subsequently lost in attempted chromosomal preparations. Of the remaining 25 cultures, 10 had abnormal karyotypes. These consisted of one monosomy-3, three trisomy-16, one mosaic trisomy-16, one trisomy-F (19-20), an XO, two polyploid, and an unusually long unidentified translocation chromosome karotypes. The remaining 15 cultures had normal karyotypes. The sex ratio as determined by sex chromatin was: males, 13 and females, 15. Eleven were confirmed chromosomally to be XY males and 13 to be XX females. Two of the trisomy-16, the mosiac trisomy, and the polyploid fetuses were males; the other four fetuses with abnormal karyotypes were females. The sex of the XO specimen could not be ascertained.