In our continuing development of a roentgenographic method of determining age, race, and sex of cadaveric material, an absolutely distinctive pattern of ossification of the costal cartilages in older women has been identified. This ossification pattern has been found only in women over the age of 50 years and largely is restricted to those over 60 (i.e., remotely postmenopausal). Not encountered in men, this age/sex distinctive pattern is found in about one-third of the adult female autopsy population. It consists of rounded, solitary, or coalescent ossified foci confined to the central portions of the costal cartilages. These foci do not extend to the perichondrium and only very rarely involve the peristernal junctions. When this x-ray pattern is present, the decedent can be identified as an elderly female with great certainty.