Background: Upper urinary tract transitional cell carcinoma (UUT-TCC) is traditionally managed with nephroureterectomy as the gold standard treatment. However, less invasive approaches such as retrograde ureteroscopic laser ablation may be considered in selected patients. External beam radiotherapy can also serve as an adjunctive or alternative option in non-surgical candidates. Case Presentation: A 94-year-old female patient presented with synchronous pathologies, including a ureteral and bladder tumor on one side and a ureteral stone on the contralateral side. She underwent emergency intervention due to acute postrenal renal failure. Although nephroureterectomy is the standard of care for ureteral tumors, it was not feasible in this patient due to advanced age and clinical condition. Therefore, ureteroscopic laser ablation was performed. As complete remission could not be achieved, adjuvant external beam radiotherapy was subsequently administered. The bladder tumor was monitored with cystoscopic follow-up, and the patient has been managed with long-term JJ stenting. Conclusion: There is no standardized treatment algorithm for UUT-TCC in cases where nephroureterectomy is not a viable option for the patient. Minimally invasive approaches such as ureteroscopic ablation may be effective in low-grade and small tumors, while radiotherapy may represent a viable option in high-grade or larger lesions. Individualized, multimodal management should be considered in such complex cases.