We describe a case of a solitary fibrous tumor of the buccal mucosa and report the results of immunohistochemical studies of the lesion. Solitary fibrous tumors are extremely rare in the intraoral region. These tumors are generally difficult to diagnose because of their broad range of morphologic characteristics. We regard the expression of CD34 within the appropriate clinical and morphologic setting, in the absence of reactivity for other specific markers of differentiation, as evidence supporting the diagnosis of solitary fibrous tumor.