Eight naturally mummified bodies from a low valley archaeological site (Az-75) near the modern port city of Arica in extreme northern Chile were studied. They represent part of the prehistoric cultural phase locally called "Alto Ramirez", that followed the Chinchorro culture in the coastal area of northern Chile between about 1000 B.C. to A.D. 500. Radiocarbon results from this sample dates this group between 350 B.C.-A.D. 500. Anatomic findings in six bodies indicate evidence of lobar pneumonia from which they had recovered, while in two bodies pneumonia was the cause of death. Their agricultural occupation and the naturally dusty condition of the air in this desert región contributed to the development of silicate pneumoconiosis. Chemical reconstruction of their diet revealed that, in contrast to their marine subsistence predecessors (Chinchorros), the Alto Ramirez people relied substantially on agropastoral subsistence strategies. However, exploitation of the conveniently available marine resources constituted about one-third of their diet. Fish tapeworm infection (Diphyllobothrium pacificum), so commonly found among the Chinchorros, was absent in these bodies, suggesting they cooked their fish. If this sample is characteristic of their entire population, the introduction of agropastoralism to this coastal area was accompanied by a high level of pulmonary infections. We have initiated study of a much larger sample of mummies from all northern Chile prehistoric populations to determine whether differences in pneumonia frequency exist in these groups