Abstract We firstly reported the electrocaloric properties in relaxor (1− x − y )NaNbO 3 – y BaTiO 3 – x CaZrO 3 ceramics, and high electrocaloric effect (∆ T ~0.451 K and∣∆ T /∆ E ∣~0.282 Km/MV) can be realized in the ceramics ( x  =   0.04 and y  =   0.10) under low temperature and low electric field. Relaxor behavior of NaNbO 3 ceramics can be found by doping both BaTiO 3 and CaZrO 3 . In addition, optimized piezoelectric effects ( d 33 ~235 pC/N and d 33 * ~230 pm/V) can be observed in the ceramics ( x  =   0.04 and y  =   0.10) due to the involved morphotropic phase boundary ( MPB ). Excellent piezoelectric effect (ie, d 33 ~330 pm/V at 41°C, and d 33 *~332 pm/V at 60°C) can be found because of the characteristics of MPB . Good temperature reliability of piezoelectric effect can be shown because of both MPB and relaxor behavior. We believe that the ceramics with high electrocaloric effect and good piezoelectric effect can be considered as one of the most promising lead‐free materials for piezoelectric devices.