To study a possibility of selective laser action on atherosclerotic plaques and normal vessel wall a set of laboratory experiments was performed. We used XeCl-laser with a Raman shifting cell and Nd-YAG laser with a frequency doubler, tripler, and quadrupler. It allows us to compare the results of laser action on tissue in a broad spectral range. The laboratory setups permit us to vary parameters of laser radiation such as pulse repetition rate, duration, energy, and power density. All samples were subjected to detailed morphological study. In particular, experiments with XeCl-laser demonstrate that the specific vaporization energy decreases when the laser energy increases. The penetration depth of laser radiation was considerably less than is to be expected from the measurement of absorption factor at 308 nm. Moreover, the absorption spectrum of the tissue after irradiation was absolutely different from the initial tissue absorption spectrum. Therefore, the two-photon processes play the main part in the interaction of high-power laser-light with tissue. Thus the laser pulse duration is to be considered as one of the most important parameters in this case. It is shown also that IR radiation at 1.06 mkm is quite effective to penetrate into calcified plaques. Laser angioplasty is still to be considered as a promising technique for treatment of vascular diseases. However, the discussion about the type of laser to be used for this purpose has not yet been finished.