A low temperature, high yield hydrothermal route has been discovered for the phase-pure synthesis of the multiferroic BaMF4 (M = Mg, Mn, Co, Ni, and Zn) family. The synthesis involves the use of CF3COOH instead of HF in an aqueous medium and, under the correct conditions, produces pure and polycrystalline BaMF4. In addition to the synthetic description, second-harmonic generation, thermogravimetric, and differential scanning calorimetry data are presented.