In accordance with the present invention, there is provided herein a method of increasing the strength of wet glass fiber mats prepared by the wet-laid process. The wet-strength of such freshly prepared glass fiber mats are improved in this invention by treating the wet mat with a dilute solution of an anionic polyelectrolyte. As a feature of the invention, the wet-strength of such mats are increased substantially so that they may be conveniently handled and transferred, even manually, for further processing, e.g. for applying binders and drying, into the finished glass fiber mat product.