This report describes the pulsed laser-induced process of noble metal flakes and nanoparticles (NPs) in liquids studied by an in-situ extinction spectroscopy which allowed detection of time-dependent events such as pulverization of flakes concomitantly with growth of nanoparticles (NPs) and splitting of NPs into smaller particles. Two key observations were made in the present study. First, we observed a remarkable spectral modification ascribable to a size reduction during the 532 and 1064 nm laser ablation of the flakes from NPs with a characteristic surface plasmon (SP) band to much smaller NPs (<2−3 nm diameter) devoid of the SP band in neat and highly concentrated dodecanethiol solutions at moderate laser fluences of 0.7−1.3 J/(cm2 pulse). Previously production of such small particles was not feasible by the 1064 nm laser light. Only in solvents that thermally decompose by laser irradiation to give graphite shells to cover NPs or by two-step size reduction procedures, i.e., initial formation of NPs fo...