BACKGROUND Angiogenesis is the formation of new blood vessels from pre-existing vasculature. Many factors and substances may stimulate angiogenesis and exhibit proliferative effect. In this study, we aimed to investigate the angiogenic and proliferative effects of sodium nitrite. MATERIAL AND METHODS The angiogenic activity of sodium nitrite was examined in vivo in the chick chorioallantoic membrane (CAM) model and in vitro in tube formation assay of human umbilical vein endothelial cells (HUVECs). The proliferative activity of sodium nitrite was also determined through MTT assay on HUVECs. RESULTS In CAM assay, sodium nitrite had an angiogenic effect especially at high concentrations compared with the control group and this was statistically significant. There was a proliferative effect on HUVECs in the presence of sodium nitrite for 24 and 48 h, and this was statistically significant (p<0.05). Comparing the tube length/area ratio values, there was statistically significant increase in the sodium nitrite group compared to the control group (p<0.05). CONCLUSIONS The results provide evidence that sodium nitrite induces angiogenesis in vitro and in vivo.