The aim of this study was to investigate expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in invasive pituitary adenomas (IPAs). The streptavidin peroxidase immunohistochemical method was employed to detect their expression in 40 cases of IPA and 40 of non-invasive pituitary adenoma (NIPA). TNF-α and IL-6 were found to be upregulated in IPA tissue compared with that of NIPA (P < 0.05). These proteins may therefore play important roles in the occurrence and progression of IPA.