Using a variety of skeletal and dental stress indicators, an assessment of the health and disease of the indigenous inhabitants of the Mariana Islands, the Chamorro, is made. The major hypothesis to be tested is that the Chamorro were relatively healthy and that deviations from the expected, as well as inter-island variation, may reflect environmental, ecological, and cultural differences. The major skeletal series surveyed include sites on Guam (N = 247 individuals), Rota (N = 14), Tinian (N = 20), and Saipan (N = 102). The majority of the specimens are from the transitional pre-Latte (AD 1-1000) and Latte (AD 1000-1521) periods. These data derive primarily from unpublished osteological reports. The indicators of health and disease surveyed include mortality and paleodemographic data, stature, dental paleopathology, cribra orbitalia, limb bone fractures, degenerative osteoarthritis, and infectious disease (including treponemal infection). Where appropriate, tests of significance are calculated to determine the presence of any patterning in the differences observed within and between the skeletal series. Information recorded in prehistoric Hawaiians provides a standard for external comparisons. Several of the larger skeletal series surveyed have paleodemographic features that are consistent with long-term cemetery populations. Females and subadults are typically underrepresented. Most subadult deaths occur in the 2-5 year age interval. Life expectancy at birth ranges from 26.4 to 33.7 years. A healthy fertility rate is indicated for these series. The prehistoric inhabitants of the Mariana Islands were relatively tall, exceeding living Chamorros measured in the early part of the present century. The greater prevalence of developmental defects in the enamel suggests that the Chamorro were exposed to more stress than prehistoric Hawaiians. The low frequency of cribra orbitalia further indicates iron deficiency anemia was not a problem. There are generally low frequencies of dental pathology in the remains from the Mariana Islands. Betel-nut staining is relatively common in all series which may help to explain the relatively low prevalence of dental pathology. Healed limb bone fractures are rare in these skeletal series; the frequency and patterns of fractures suggest accidental injury as the main cause. Greater physical demands involving the lower back region are indicated by a high frequency of spondylolysis, or stress fracture in the lumbar vertebrae in the Chamorro. Likewise, advanced degenerative bone changes, while of low occurrence, are significantly greater in the Chamorro than Hawaiians. The prevalence of skeletal and dental indicators of stress was generally higher in the smaller islands of the Mariansas chain (e.g., Rota), islands with fewer resources to buffer environmental catastrophe. Bony changes suggestive of treponemal (probably yaws) disease are common in most of these Marianas Islands skeletal series.