Among the different metals displaying high selectivity towards HCOOH production from CO2 electroreduction, Sn exhibits the lowest toxicity and represents one of the best options in terms of cost and selectivity [1]. However, small size capping agent free Sn nanoparticles are difficult to be synthesized and present low structural stability due to Ostwald ripening. For this reason, SnO2 nanoparticles have been recently proposed in the literature as an interesting alternative material for HCOOH production [2], since SnO2 presents much higher structural stability under electrochemical conditions. The present communication is devoted to the study of high surface area SnO2 nanoparticles (2 nm in diameter), synthesized by a facile hydrothermal microwave-assisted method, as an alternative highly efficient and stable electrocatalyst for continuous HCOOH production from CO2 electroreduction. Our experimental results display high production values using SnO2 nanoparticles supported on a carbon based gas diffusion cathode (10 cm2 of geometrical area) in a filter-press reactor configuration. Figure 1 exhibits an almost constant production of HCOOH as a function of time, which demonstrates a longterm stability of SnO2 nanoparticles during CO2 electroreduction in aqueous solution.