Short-term cultures from a primary carcinoma of the Fallopian tube, a tumor type not characterized before by chromosome banding, were examined cytogenetically. Complex chromosome aberrations were found in all mitoses, yielding the karyotype 41,XX,del(1)(p34),del(2)(q31),i(8)(q10),-9, + dic(9;19)(p13;p13), der(12)t(9;12)(p13;q22),-13,-16,-17,-18,-19,-22, +r [61]/84-86,idemx2[15]. Several of the aberrations in the present case are similar to changes found in adenocarcinomas of other organs, including carcinomas of the ovaries and uterus, indicating pathogenetic similarities between Fallopian tube malignancies and the more common gynecologic cancers.