Introduction:Surgery is the preferred treatment for basal cell carcinoma (BCC), locally advanced or metastatic BCC, radiation therapy or systemic therapy can be considered. Programmed death receptor 1 (PD-1) inhibitors are rarely used to treat cutaneous BCC. In the present case, we found that tislelizumab, a PD-1 immunosuppressant, had a positive effect on BCC.Patient concerns:A 74-year-old male patient presented with a mass in the left back in October 2021, which was surgically removed and diagnosed as BCC. The patient was diagnosed with squamous lung cancer after presenting with a cough and coughing up a small amount of white, sticky sputum in December 2021.Diagnosis:BCC and squamous lung cancer.Interventions:Docetaxel + nedaplatin systemic chemotherapy combined with tislelizumab immunotherapy.Outcomes:Both BCC and squamous lung cancer were significantly reduced in size.Conclusion:After 2 cycles of immunotherapy with tislelizumab, the lung tumor shrank, the back mass disappeared, and the wound healed.