The phases of PLZT, (Pb,La)(Zr,Ti)O-3, or L/Z/T for L < 12 and T < 10 were detected via determination of capacitance at varying temperatures at 0 field and via polarization at varying fields at room temperature and at selected elevated temperatures. It was possible to determine two different orthorhombic phases, and three rhombohedral (hexagonal) phases, one of which only exists at elevated temperatures. Two sets of phase diagrams were constructed with the phases as a function of temperature, and electric field, respectively. Temperature/field phase diagrams for 0/100/0, 2.95/5, and 4/95/5 were also constructed. A comparison was made between room-temperature and 0 field PLZT phase diagrams determined via X-ray diffraction, capacitance, and polarization.