The aim of this study was to diagnose and describe extensive inflammatory changes in a child's skeleton from Wawrzeńczyce, (the medieval period). The aim of the analysis was to determine the nature of the inflammatory changes and their etiology by means of macroscopic techniques as well as X-ray analysis. The tests revealed that the individual suffered from a hematogenous multifocal osteitis. This condition might have been a result of an acute or sub-acute osteitis, and the untreated form of osteomyelitis might have contributed to the infection of the entire developing organism, leading to death.