This work describes the synthesis of dicalcium silicates doped with titanium. Rice hull ash was used as the source of silica. Starting reagents (SiO2, CaO, and TiO2) were used in stoichiometric proportion in order to mantain a (Ca+Ti)/Si ratio=2. Aqueous dispersions were prepared and submitted to an ultrasonic bath for 60 min. After drying, the solids were calcined at 800 degrees C. Chemical analyses were performed by X-ray diffraction and infrared spectroscopy. Dicalcium silicates doped with 5% of titanium were obtained. Overall, the performance of mortars containing 20% of dicalcium silicate doped with titanium was similar to mortars prepared from portland cement.