Activation of angiogenesis under laser irradiation is one of the feasible explanations for long lasting treatment effects of laser therapy. The aim of the current study is the investigation of red low level laser light influence on angiogenesis study in vitro, and comparison with effects of vascular endothelial growth factor (VEGF) application. The study was done on rat thoracic aortal rings. Samples of group 1 served as control, group 2 samples were incubated with VEGF, group 3 samples were irradiated with low level laser (660 nm, 20 mW) during 10 min, and group 4 samples were incubated with VEGF and received 10 min of laser irradiation. Low level laser irradiation activates the process of angiogenesis. In the control group angiogenesis of new vessels was not detected. Laser irradiation promoted angiogenesis. The area covered by new vessels was 1,9±0,29 mm2 and the maximal length of vessels was 0,75±0,lO mm. No statistical difference was discovered between laser irradiation and VEGF application. After combined influence of VEGF and laser light irradiation the area covered by new vessels was 6,98±0,88 mm2 and the maximal length of vessels was 1,7±0,23 mm. So, laser irradiation can intensify effects of VEGF on angiogenesis.