Piezoelectric properties k33 and d33 of 0.67 Pb(Mg1/3Nb2/3)O3–0.33 PbTiO3 single crystals grown by a modified Bridgman method were measured in the temperature range of 20–150 °C. Recoverability of the properties after the samples were heated to 110 °C, above the ferroelectric–ferroelectric (F–F) phase transition temperature of the composition, was found. From 20 to approximately 80 °C, k33 increases slightly, while d33 is almost doubled. Between approximately 90 and 100 °C, k33 decreases sharply to roughly a level of PZT-5 ceramics and d33 decreases to about 700 pC/N. They increase again with further increase of temperature; at 140 °C they attain 0.74 and approximately 1300 pC/N, respectively, and then decrease quickly and approach zero at about 150 °C. When heating to 110 °C followed by cooling to room temperature, the property decay is small. After more than one dozen heating–cooling cycles, k33 and d33 tend to be stable at 0.89 and approximately 1220 pC/N, respectively. The results might be helpful for device design and applications of PMN–PT single crystals.