Cytogenetic studies of childhood ovary tumors have been poorly described. In the present article, the cytogenetic findings of an ovarian teratoma with malignant germ cell (yolk-sac) component occurring in an 8-year-old female are detailed. GTG-banding showed a karyotype of 46,XX, t(3;20)(q27;q13.3) [4]/46,XX, del3q27 [3]/46,XX [30]. Previous studies have demonstrated common sites of loss of heterozygosity at 3q27-q28 region in different types of cancer, suggesting the presence of tumor suppressor genes within this region.