Xeroderma pigmentosum (XP) is an autosomal recessive disorder of nucleotide excision repair, characterized by hypersensitivity to ultraviolet light (UV) radiation. In individuals with XP, the incidence of non-melanoma skin cancers prior to the age of 20 years is approximately 10,000 times that seen in the general population. The most common cause of death in this patient population is skin cancer, including metastatic melanoma and metastatic cutaneous squamous cell carcinoma (cSCC). Sun avoidance is the main mode of skin cancer prevention in XP patients. However, the development of invasive skin cancers at an early age and challenges associated with avoiding sun exposure highlight the critical need for additional cancer prevention strategies in this high-risk population. We report cSCC incidence before and after starting immune checkpoint blockade (ICB) therapy in a single-center case series of three XP patients. Our findings highlight the effectiveness of ICB therapy for cSCC prevention in XP. This article is protected by copyright. All rights reserved.