Mixed oxides of Zn and Sn are of interest for gas sensing and diverse optoelectronic applications, and therefore new approaches to prepare such nanomaterials are anticipated. This study reports, for the first time, on the use of laser ablation in liquid applied to a Sn-Zn alloy and describes obtained products. Core@shell Sn@SnO and ZnO nanoparticles are shown to be produced by millisecond pulsed laser upon ablating eutectic Sn-Zn alloy in water. The as-prepared materials were found to contain surface hydroxide layers which were dehydrated to SnOx and ZnO when higher laser energy fluence was applied or when the products were post-treated at 200C in air. The morphology, shape and size distribution, phase and chemical composition of prepared nanoparticles were studied as a function of laser parameters used during their preparation. Increase in pulse energy was found to result in fabrication of finer particles. It was found that while both metallic Sn and SnOx were presented in the product, zinc was always oxidized to its oxide ZnO. In addition, when properly annealed, the produced nanomaterial demonstrated gas sensing response towards ammonia at room temperature.