Transurethral resection of the prostate performed for histopathological diagnosis revealed squamous cell carcinoma.<h4>Conclusion</h4>Hereby, a rare case of secondary squamous cell carcinoma of the prostate after radiotherapy for adenocarcinoma was reported, which was found after 11 years of radiotherapy with symptom of dysuria including urinary hesitancy, difficulty, pain during urination, and low-serum prostate-specific antigen levels. The gene discussed is KLK3; the disease is squamous cell carcinoma.