A series of shear thickening fluids (STF) were prepared and characterized by Rheometer. The stab resistance of Kevlar and ultrahigh molecular weight polyethylene (UHMWPE) non-woven fabrics impregnated with STF were investigated and found to exhibit significant improvements over neat fabric targets of equivalent weight. Specifically, dramatic improvements in stab resistance (knife threat) were observed. These novel materials could be potentially used to fabricate flexible body armors which provide improved protection against both stab and ballistic threats.