In modern clinical medical practice, middle-ear infection is a frequently reported condition. If untreated, persistent inflammation caused by infection may lead to perforation of the mastoid process or other portions of the temporal bone. When the middle-ear abscess penetrates the surrounding bone and invades the mastoid process, it causes mastoiditis. Abnormal osseous fistulae were observed on the temporal bones of individuals M137 and M199, which were unearthed in Qufu Olympic Sports Center Cemetery in Qufu City, Shandong Province, and date to the Warring States to the Han Dynasty (475 BCE–220 CE). Microscopic observation and CBCT were used to examine the lesions. A differential diagnosis suggests that the lesions were related to mastoiditis, and based on reference studies, burial information, and paleopathological observation, pollution in the living environment and poor living conditions may be potential factors that caused individuals M137 and M199 to suffer from mastoiditis. The two examples from Qufu are the earliest reported cases of mastoiditis from China; however, infections in the middle ear often go unnoticed in archaeological samples.