The purpose of this study was to investigate the effect of operating conditions on nugget diameter and joint strength of KOVAR alloy and SPCC steel in projection welding of dissimilar metals. All projection welds were produced with a capacitor charging power supply. Harris and Riley type projection was embossed on SPCC steel sheet. The nugget diameter was estimated using a peel test. The lap-joint strength of projection welds was evaluated using a tensile-shear test. The results indicated that the nugget diameter and joint strength increase as the weld current increase. Increasing the electrode force will produce a small nugget diameter. The nugget diameter of projection welds is a good indicator of the lap-joint strength.