Abstract: A method and apparatus for surgical and dermatological treatment using a multi-wavelength laser system includes a primary laser beam generator optically pumped by a semiconductor laser diode. A portion or all of the optical pumping energy may be outputted with the primary laser beam output to form a multi-wavelength treatment beam. A frequency doubling medium, such as a KTP or LBO crystal, may be imposed in the output of the laser beam generator to produce an additional wavelength that may be combined into the multi-wavelength treatment beam. To achieve high peak power pulse laser output, a Q-switch element can be placed in front or in back of the laser crystal. Alternatively, the laser system may output only the wavelength of the semiconductor laser diode pumping system. The selection of one or more wavelengths provides a wider range of treatment modalities using a single laser system, without creating problems attendant with the complexity and maintenance of prior art multi-wavelength laser systems.