Laser lithotriptor for crumbling calculi (stones) in the urinary or biliary system is discussed. The source of a power optical radiation is a flashlamp-pumped dye laser using iminocoumarin G-283 and operating at 530 nm wavelength in the repetitively pulsed regime with the pulse duration of 1 to 2 ms, pulse repetition rate of 1 to 10 Hz, and average power up to 2 W. The optical waveguide with 400-microne core is used.