(1 − x)(Bi0.90Li0.10)(Sc0.90Ta0.10)O3xPbTiO3 (BLSTPTx; x = 0.60–0.65) ceramics were prepared using the conventional mixed oxide method. X-ray diffraction analysis revealed that BLSTPTx has a pure perovskite structure. In the vicinity of the morphotropic phase boundary, which was observed in the compositional range 0.61 ≤ x ≤ 0.62 from phase structure measurements, the BLSTPTx ceramics showed enhanced piezoelectric properties: piezoelectric constant d33 = 516 pC/N, planar electromechanical coupling factors kp = 57%. The temperature of the permittivity maximum increased with increasing measurement frequency, over the range 302–313 °C, higher than that of conventional relaxor materials such as Pb(B1B2)O3PbTiO3 systems. The ceramics show relaxor ferroelectric features.