Laser ablation in liquid (LAL) is known to be a promising method for synthesizing metal nanoparticles. In this study, gold and silver nanoparticles were fabricated by ultrasonic-assisted LAL. Gold and silver plates were ablated using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, with a wavelength of 532 nm and energy of 26.4 J cm(-2), in distilled water in the presence and absence of an ultrasonic field. The fabricated nanoparticle colloidal solution was analyzed with an ultraviolet-visible (UV-vis) spectrometer, a transmission electron microscope (TEM) with energy-dispersive X-ray spectroscopy (EDS), and zeta-potential measurement. The craters on the silver plates were analyzed by a scanning electron microscope (SEM), a laser microscope, and MATLAB to observe their morphology and calculate the volume to obtain the concentration of the fabricated nanoparticle solution. Optical emissions were observed to study the characteristics of the laser. The results showed that ultrasonic-assisted LAL has considerable potential for fabricating superior metal nanoparticles.