Solitary fibrous pleural tumors are rare masses of mesenchymal origin that may be mistaken for mesothelioma. A positive staining of vimentin, negative staining of cytoplasmic keratin, and expression of the CD34 antigen can confirm the presence of a solitary fibrous pleural tumor. Although most tumors of this type are benign, they possess a malignant potential and thus should be excised. We report a case of a 63-year-old man who had an inconclusive biopsy of a lung lesion 15 years ago. Further testing after excision revealed a solitary fibrous pleural tumor. A brief discussion of the clinical presentation and incidence of these tumors is included.