Integrated laser Doppler velocimeters (LDVs) using integrated waveguide technology are reviewed. LDVs have been widely used to measure the velocity of a fluid flow or rigid object in various research and industries. However, bulk optical systems used in conventional measurement need special care from temperature change and vibration, which become the expected sources of uncertainty in measurement, due to large optical path length. Therefore, the optical system should be more compact. The LDV can be drastically reduced by using a planar lightwave circuit (PLC). The possibility for realizing several types of novel integrated LDVs, including a wavelength-insensitive LDV, a scanning LDV and a multi-point LDV, is discussed.