AIM: To evaluate anti-angiogenic effect of tenomodulin (TNMD) and ranibizumab on cell proliferation and capillary-like morphogenesis of vascular endothelial cells under the stimulation of vascular endothelial growth factor (VEGF) in vitro. METHODS: The effects of TNMD and ranibizumab on VEGF-induced proliferation of human umbilical vein endothelial cells (HUVECs) were evaluated by MTT assay, and the effects of TNMD and ranibizumab on capillary-like structures formed by HUVECs under the stimulation of VEGF were examined in culture. Capillary-like morphogenesis of HUVECs was quantitatively evaluated, and total lengths of tube-like structures per field were measured in a masked way. RESULTS: HUVECs with both ranibizumab and TNMD protein showed MTT reduction in VEGF-stimulated cell proliferation as expected, while MTT absorbance in the HUVECs with TNMD was significantly declined than that with ranibizumab (P<0.01). The capillary-like structures formed by HUVECs were markedly impaired by the presence of both TNMD and ranibizumab in the culture medium. The total length of the capillary-like structures per field was significantly shorter in the medium with TNMD than that of ranibizumab (P<0.01). The inhibitory effect of TNMD on tube formation in vitro angiogenesis was significantly stronger than that of ranibizumab. CONCLUSION: TNMD may have stronger inhibitory effect than ranibizumab on in vitro angiogenesis.