Abstract: A method precipitating struvite in wastewater uses a magnesium sacrificial anode as the only source of magnesium. A high-purity magnesium alloy cast anode was found to be very effective in recovery of high-quality struvite from water solutions and from supernatant of fermented waste activated sludge (WAS) from a high-purity oxygen wastewater treatment plant. Struvite purity was strongly dependent on the pH and the electric current density. Optimum pH of the solution was in the broad range between 7.5 and 9.3, with struvite purities exceeding 90%. The precipitated struvite accumulated in bulk liquid with significant portions attached to the anode surface from which regular detachment occurred.