A cement mortar is provided which is mixed with a liquid media, preferably either water or aqueous latex, for use as a thin-set mortar, medium bed mortar, underlayment mortar and/or grout (pointing mortar). The mortar or grout contains cement, sand and a water retaining agent and is improved by employing an aramid fiber in the mortar. A p-aramid fiber is preferred and it is highly preferred to use the polymer fiber in a pulp form which has a fibrillated structure. The overall performance properties of a cement-based mortar or grout such as a thin-set mortar are significantly improved including sag resistance, open time, bond strength, flexibility, heat aging and water immersion strength.