The removal of PO4 and NH4 from wastewaters was investigated by stimulating the formation of precipitates containing PO4 and NH4 in granulated sludge in UASB methanogenic fermentation, In a synthetic wastewater containing volatile fatty acids, the removal efficiencies of PO4 and NH4 were 85 (influent = 406 mg/l) and 60% (influent = 100 mg/l), respectively, when 8 mM Ca and 8 mM Mg were added in the influent. In a heat-treated liquor of sewage sludge, a PO4 removal efficiency of 70% (influent = 53 mg/l) was achieved by the addition of 2 mM Ca and 3.5 mM Mg; removal of NH4, however, was not observed during the experimental periods.