The present invention relates to liquid formulations of poxvirus, in particular vaccinia virus, stable during storage. Such stable liquid formulations comprise a) a poxvirus, preferably a vaccinia virus, b) a pharmaceutically acceptable buffer, c) a monovalent salt, d) a pharmaceutically acceptable disaccharide or sugar alcohol, and e) a pharmaceutically acceptable chelating agent, wherein the pH of the formulation is comprised between 6.5 and 8.5.