Acidified aqueous metal nitrate solutions containing dissolved phosphate ions yield the corresponding metal phosphates upon cathodic reduction. In alkaline earth metal containing electrolytes [phosphate source, (NH4)(2)HPO4], the phase obtained is MHPO4 (M = Sr, Ba). Controlled growth of adherent micrometer-thick coatings of SrHPO4 could be achieved on the cathode substrate. In Mg, Co, and Ni containing electrolytes, electrosynthesis yields the hydrates of the corresponding NH4MPO4 (M = Mg, Co, Ni) at low (25 mA cm(-2)) current densities, while at high (60 mA cm(-2)) current densities, X-ray amorphous metal orthophosphates are obtained. The use of Na3PO4 as the phosphate source also yielded X-ray amorphous products. In the Co system, the electrosynthesized phase, (NH4CoPO4H2O)-H-. was different from that obtained by chemical precipitation. This study demonstrates the versatility of electrosynthesis.