Inflammatory pseudotumors are benign lesions that are rarely reported in the head and neck. Moreover, intraosseous inflammatory pseudotumors of the maxilla are extremely rare, with less than 10 cases reported. A 52-year-old woman presented with recurrent dental infections; computed tomography scan of the osteolytic maxillary bone lesion and incisional biopsy were performed. Histopathological examination revealed that the lesion was composed of fascicles of fibroblasts and myofibroblasts, in addition to sheets of plasma cells, lymphocytes, and occasional other inflammatory cells. An infiltrative growth pattern was observed. Immunohistochemical staining confirmed an inflammatory pseudotumor. A partial maxillectomy was performed. There was no evidence of recurrence during the 4-month follow-up period. Inflammatory pseudotumors should be considered when treating destructive maxillary lesions. Immunohistochemical staining was performed to confirm polyclonal plasma cell proliferation.