Abstract Thick films of niobium doped lead zirconate titanate (PNZT) were prepared from a sol-gel/PZT powder composite slurry. The effects of adding different amounts of sol-gel derived lead germanium oxide (PGO) as sintering aid were examined. Four layers of composite, with intermediate sol infiltrations, were deposited by spinning onto Pt/Ti/SiO 2/Si substrates followed by drying and annealing. Addition of PGO enhanced the densification process at a temperature as low as 770 °C. It resulted in an increase in the film properties that depended upon the level of PGO addition. Film properties were assessed by measuring the capacitance and dielectric loss. d 33,f and e 31,f piezoelectric coefficient measurements were carried out after poling at 10 V/μm for 5 min at 130 °C. A maximum relative permittivity of 500 was observed between 5 and 8 wt.% PGO addition. The maximum in d 33,f was found to be about 40 pC/N. Additions between 7 and 10 wt.% PGO led to the maximum e 31,f piezoelectric coefficient of about −1.5 C/m 2.