Protein delivery to primary cells by protein transduction domain (PTD) serves as a novel measure for manipulation of the cells for biological study and for the treatment of various human conditions. Although the method has been employed to modulate cellular function in vitro, only limited reports are available on its application in the replacement of deficient signaling molecules into primary cells. We examined the potential of recombinant proteins to compensate for defective cytosolic components of the NADPH oxidase complex in chronic granulomatous disease (CGD) neutrophils in both p47(phox) and p67(phox) deficiency. The p47(phox) or p67(phox) protein linked to Hph-1 PTD was effectively expressed in soluble form and transduced into human neutrophils efficiently without eliciting unwanted signal transduction or apoptosis. The delivered protein was stable for more than 24h, expressed in the cytoplasm, translocated to the membrane fraction upon activation, and, most importantly able to restored reactive oxygen species (ROS) production. Although research on human primary neutrophils using the protein delivery system is still limited, our data show that the protein transduction approach for neutrophils may be applicable to the control of local infections in CGD patients by direct delivery of the protein product.