Ablation of Au and Ag targets in water by a Cu vapor laser generates Au and Ag sols. The metal nanoparticles obtained after evaporation are disk-shaped (diameter in the 20-60 nm range, thickness of few nanometers). Their formation is observed at laser fluence between 10 and 20 J/cm(2). Both aqueous sols are characterized by well-resolved plasmon bands around 400 run (Ag) and 520 mn (Au.).