Laser-based ultrasonic (LBU) techniques provide a number of advantages over conventional ultrasonic methods such as higher spatial resolution, non-contact generation and detection of ultrasonic waves, and ability to operate on curved and rough surfaces [1]. In earlier papers, the present authors have described fiberized tunable laser ultrasonic sources [2,3], and fiber-optic heterodyne and Sagnac interferometers for detection of ultrasound [4,5]. In this paper we present a new laser based technique--Scanning Laser Source (SLS) technique--for the detection of small surface-breaking cracks on rough and curved surfaces. This technique allows detection of flaws by monitoring the variations of ultrasonic amplitude and frequency (flaw signature) as the laser ultrasonic source is scanned across the object and passes over any defects. Typical flaw signatures for different kinds of surface breaking defects are obtained. The results of application of the SLS technique for inspection of a turbine disk are presented.