In the past two decades, significant advances have been made in diagnosing and treating chronic granulomatous disease (CGD), an inherited immunodeficiency where phagocytes fail to generate superoxide and other reactive oxygen species that are essential for microbial killing. This chapter summarizes the molecular genetics and pathophysiology of CGD, outlining the mechanisms leading to its clinical symptoms. We present current treatment strategies, focusing on hematopoietic stem cell gene therapy, which offers a potentially curative approach by restoring functional phagocytes. We discuss gene addition with viral vectors, as well as recent gene editing strategies aimed at targeted mutation correction. Finally, we outline a future perspective on CGD gene therapy, analyzing challenges and success factors and comparing the therapeutic potential of viral gene addition and gene editing approaches to provide a safe and effective treatment for CGD.