ObjectiveTo investigate the expression of tumor necrosis factor-α (TNF-α) in prostate cancer tissue and explore its relations with tumor angiogenesis. MethodsThe expression of TNF-α and CD105 were detected with two-step immunohistochemical staining technique in 20 cases of benign prostatic hyperplasia and 50 cases of prostate cancer between January 2010 and January 2012, and microvessel density (MVD) marked with CD105 was also measured. ResultsThe expressions of TNF-α and CD105 were higher in prostate cancer (41.72±8.67, 20.15±2.67) than those in benign prostatic hyperplasia (21.01±3.85, 4.34±1.67) (t'=13.990, P<0.001; t'=29.771, P<0.001). TNF-α and MVD were not correlated with age and size of tumor, but were positively correlated with tumor differentiation degree (rs=0.847, P<0.001; rs=0.776, P<0.001) and negatively correlated with clinical grades (rs=-0.769, P<0.001; rs=-0.842, P<0.001). ConclusionThe result indicates that over expression of TNF-α exists in prostate cancer. It may play an important role in the anginogenesis and carcinogenesis of prostate cancer.