Human papillomavirus (HPV)-related lower genital cancers, including cervical cancer, anal squamous cell carcinoma (SCC), vaginal cancer, vulvar cancer, and penile cancer, pose a significant health burden, with approximately 45,000 new cases diagnosed annually. Current effective treatment modalities include chemoradiotherapy, systemic chemotherapy, and immune checkpoint inhibitors (ICIs). The tumor microenvironment in HPV-related cancers is characterized by immune evasion mechanisms, including the modulation of immune checkpoints such as PD-L1/PD-1. HPV oncoproteins E5, E6, and E7 play crucial roles in this process, altering the expression of immune inhibitory molecules and the recruitment of immune cells. ICIs, such as programmed cell death protein 1 (PD-1) inhibitors, have shown efficacy in enhancing the immune response against HPV-associated tumors by blocking proteins that allow cancer cells to evade immune surveillance. Recent studies have demonstrated that HPV-positive tumors exhibit a more favorable response to ICI-based therapies compared to HPV-negative tumors. The integration of ICIs into treatment regimens for HPV-related cancers has been supported by several clinical trials. The inclusion of ICIs in the treatment approach for HPV-related lower genital cancers presents a promising opportunity for improving patient outcomes. Ongoing research and clinical trials are advancing our understanding of the immune microenvironment and the therapeutic potential of immunotherapy for these cancers.