A study of female mummies representing seven pre-Columbian Andean populations of Arica, Chile, dating from 1300 B.C. (Azapa phase) to A.D. 1400 (Gentilar phase), disclosed that 18 (14% of the total) had died from childbirth-complicated death (CCD). The majority of these individuals appear to have died during puerperium, three of them without complete delivery. Higher rates of CCD were found in the earlier cultural phases (1300 B.C.-A.D. 600) after which the maternal mortality rate decreased. The precise causes of this mortality are not known, but septic conditions, acute diseases, and cultural practices relating to birth are implicated.