Pu-erh tea is produced in China and known to possess medicinal properties. The anticancer and antiangiogenesis effects of fermented Pu-erh tea on HT-29 colon cancer cells and human umbilical vein endothelial cells, respectively, were examined. Two kinds of unfermented and fermented Pu-erh tea (Seven-son tea cake Pu-erh tea and Xiaguan bowl tea [X]) and green tea were used. An MTT assay showed fermented Pu-erh tea X (85% inhibition) possessed more potent anticancer activities than unfermented Pu-erh tea X (67% inhibition) and green tea (53% inhibition) (P < 0.05). Moreover, fermented Pu-erh tea X increased the number of apoptotic bodies determined through DAPI staining and flow cytometric analysis. Fermented Pu-erh tea X induced apoptosis indicated by increased expression of Bax, caspase-9, and caspase-3 messenger RNA and decreased expression of Bcl-2. Fermented Pu-erh tea X also had an anti-inflammation effect, shown in decreased expression of nuclear factor-κB-p65, inducible nitric oxide synthase, COX-2 messenger RNA and increased expression of IκB-α. Further, fermented Pu-erh teas showed stronger antiangiogenesis effects than the 2 other types of tea. After fermentation, the concentrations of gallic acid, resorcylic acid, quercetin, and kaempferol in Pu-erh tea were increased. These results collectively indicated that fermented and unfermented Pu-erh teas possess stronger anticancer and antiangiogenesis effects than green tea. Furthermore, fermented Pu-erh tea showed stronger functional activities than unfermented Pu-erh tea.