There is substantial evidence that low level laser irradiation may induce vascular relaxation leading to an improved tissue perfusion in the microvascular network [Maegawa et al. 2000]. This is relevant since adequate blood supply is an important factor in the treatment of pain syndromes in sport medicine. However, the underlying mechanisms have not been studied in depth and the corresponding reports are mainly restricted to animal models. Therefore, continuous wavelet transformation was applied to the laser Doppler signals which were recorded immediately before and after a standardized laser needle stimulation over acupuncture point Neiguan [Pe6] in 6 healthy, nonsmoking males. Five defined frequency intervals were analysed corresponding to cardiac, respiratory, neurogenic, myogenic and endothelial metabolic activity. The mean amplitude of the total spectrum [0.009-2 Hz] and the absolute and normalized amplitude of each particular interval were calculated. Current findings demonstrated insignificant alterations in skin blood flow as well as in calculated amplitudes. It seems that laser needle stimulation has no effect on peripheral blood flow and microvascular control under the conditions of the present study. However, confidence interval estimation alludes to plausible effects. Further research on LDS and wavelet analysis in terms of randomised, controlled trials with adequate sample sizes is required. References Maegawa, Y., Itoh, T., Hosokawa, T., Yaegashi, K., and Nishi, M. . Effects of Near-Infrared Low-Level Laser Irradiation on Microcirculation. Lasers Surg. Med. 27, 427-437.