The study highlights the effect of donor (Sr2+) and acceptor (Zr4+) co-doping on phase formation, microstructure, density, ferroelectric, dielectric, piezoelectric, fatigue and aging properties of (Na0.52 K0.48)(Nb0.95 Sb0.05)O3, abbreviated as NKNS, lead free piezoelectric ceramics. The composition (1–x)(NKNS)—xSrZrO3 (where x = 0.0, 0.02, 0.04, 0.06 and 0.08) were synthesized by mixed oxide route. The doping drastically affected the phase formation and the microstructure. The poling studies suggested that the material requires higher poling temperature (120 °C) for optimum properties. At the small concentration of SrZrO3, the dominant effect of acceptor doping induced ‘hybrid’ piezoelectric behavior which improved fatigue, ageing and piezoelectric properties. The mechanical quality factor (Qm) more than doubled (96) and piezoelectric charge co-efficient peaked to 157 × 10 −12 C/N for 2% SrZrO3. The study of Raman spectra ascertained that the doping influenced the nature of B–O bonding. The electrical fatigue behavior in conjunction with ferroelectric studies confirmed that due to complex doping different mechanisms work to stabilize the polarization state which influenced the ageing and fatigue behavior.