Publisher Summary This chapter deals with laser ablation. Formation of small particles at laser ablation of a solid in liquids is an inevitable phenomenon at both shock processing and machining. When a solid target is vaporized, the vapor tends to condensate as small particles. When ablation is carried out in liquid, the particles remain in liquid as a suspension. Using laser ablation of solids in liquids, colloidal particles of a large variety of materials has been fabricated in recent years, with a rise of overall interest to nanoscale sciences and nanofabrication. Compared with other methods of fabrication of nanoparticles, laser ablation in liquid has some advantages. These include: no occurrence of problems with the collection of the particles, and that laser ablation yields principally cleaner particles, because no other substances are involved in the process than the target and the liquid. The main disadvantages of the laser method are its small productivity (of order of some mg/h) and expensive equipment (laser). This chapter summarizes the optical properties of small particles as many important applications of laser-generated particles rely on their optical properties. It then describes some experimental techniques of particle generation. Furthermore, it discusses the ablation process in metal colloids, inorganic compound particles, and silicon and amorphous carbon particles. Finally, it discusses laser-energized liquid-assisted diamond synthesis.