Gold nanoparticles and cysteamine-coated gold nanoparticles are physically synthesized using the pulsed laser ablation in liquid technique, which is rapid, simple, and efficient one-step synthesis. UV-Vis analysis shows that the absorption band after cysteamine coating is shifted toward the lower wavelength range around as compared to gold nanoparticles’ absorption band around . Moreover, the change in the color of the solution is due to the aggregation of nanoparticles after cysteamine coating. From transmission electron microscopy, cysteamine coating of thickness on gold nanoparticles is successfully carried out with narrow pore size distributions. Energy-dispersive x-ray spectroscopy analysis confirms the presence of cysteamine coating. Attenuated total reflectance Fourier transform infrared spectroscopy analysis also confirms the bond linkage between gold and cysteamine species.