Abstract In this work the influence of the wavelength variation of a pulsed laser on the size distribution of gold nanoparticles, synthesized by laser ablation in liquid medium, was determined, since this technique is the most used due to its simplicity as it is not developed under strict conditions of temperature, pressure, agitation, etc. Three different wavelengths were used: (i) 532 nm, (ii) 355 nm and (iii) 266 nm, due to equipment restrictions. The distributions and sizes of nanoparticles were studied by dynamic light scattering, scanning electron microscopy and atomic force microscopy. In addition, it is shown that the spectra of the gold region determine the chemical state of the nanoparticle. The results showed that the smallest particle size was obtained with the wavelength of 266 nm with a size of 9.6 nm, while for the other wavelengths; sizes of 55.4 nm and 77.3 nm were obtained respectively. Thus, smallest average diameter of gold nanoparticles was obtained with smallest wavelength.