Of the 127 adult crania and cranial sections available for observation, 53 (42 percent) were scored for the presence of at least 1 of the 4 osseous phases. Twenty-five percent of the specimens were scored for one or two of the defined osseous responses; only 17 percent of the fractured specimens exhibited three or more of the traits. The earliest observed response to cranial fracture occurred at 5 days, which involved a single case of osteoclastic response on the ectocranial surface. In most cases, no osseous response was discernible during the first week; however, after the first week, the prevalence of both clastic and blastic activity began to increase. By the sixth week, 100 percent of the cranial fractures observed showed some form of osteoblastic and osteoclastic activity. The limited number of specimens in the late stages of healing indicate that both osteoblastic and osteoclastic activity declined somewhat, although both responses were present in over 80 percent of the observations after the sixth week. Similar to the osteoblastic and osteoclastic responses, the line of demarcation and sequestration showed a latent period followed by increasing prevalence. Sequestration, on the other hand, did not exhibit any trend. This report cautions that when calculating time elapsed since trauma, the examiner should provide only a minimal response time, given that a certain number of days elapse for a response to occur. Clearly, much work remains to be done in furthering understanding of fracture timing in dry bone specimens. It is possible that histologically assessed healing rates may differ from those reported for the current study. Sample source and data collection are described. 3 tables, 3 figures, and 20 references