INTRODUCTION: Solitary fibrous tumors (SFTs) of the bladder are rare mesenchymal neoplasms that mimic other bladder tumors, requiring a multidisciplinary approach for diagnosis and management. CASE PRESENTATION: An 81-year-old male with a 30-pack-year smoking history presented with clotting hematuria and acute renal failure. Imaging revealed a large bladder mass causing bilateral ureteral obstruction. Transurethral resection and immunohistochemical analysis confirmed an SFT. The patient underwent cystoprostatectomy with Bricker diversion, achieving full recovery. DISCUSSION: Bladder SFTs are often misdiagnosed as other spindle cell tumors. Histopathology and CD34 immunopositivity are key for diagnosis. Although typically benign, recurrence and metastasis require long-term follow-up. CONCLUSION: This case underscores the rarity of bladder SFTs and highlights the importance of accurate diagnosis and complete surgical excision for optimal outcomes.