We developed a cost-effective method to manufacture high performance-monolithic solid oxide fuel cells using nano-composite electrodes, tape-casting and single-step co-firing. NiO/YSZ–YSZ nano-composite powder comprising nano-sized NiO and YSZ adhered to core YSZ powder was prepared for anode support. LSM/GDC nano-composite cathode fired at 1400 °C had a porosity of over 20%, which was much higher than that of conventional LSM–GDC. Furthermore, the area specific resistance of the LSM/GDC cathode was 0.15 Ω cm2, which was much lower than that of the LSM–GDC and LSM–YSZ mechanically mixed cathodes. Various types of monolithic SOFC unit cells were prepared; one consisting of a NiO–YSZ anode, NiO/YSZ–YSZ anode functional layer, and LSM–GDC cathode had a current density of 0.37 A/cm2 at 0.7 V at 800 °C. Optimized monolithic SOFC consisting of NiO/YSZ–YSZ anode and YSZ electrolyte and LSM/GDC cathode had a greatly improved current density of 0.84 A/cm2.