Leiomyosarcomas (LMSs), malignant soft tissue tumor deriving from the mesoderm, account for <0.1% of all bladder malignancies. Conventionally, radical cystectomy with lymph node dissection has been advocated, though some series report that partial cystectomy is acceptable if a negative surgical margin is achieved. Here, we describe a 20-year-old young female presenting with LMS bladder. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a lobulated mass of 2.5 X 3.0 cm on the left lateral side of the bladder. The rest of the bladder appeared normal, with no gross pelvic lymphadenopathy. She performed with transurethral resection of bladder tumor (TURBT). She was diagnosed as LMS though histopathology and immunohistochemistry. Repeat-TURBT was implemented 30 days after... the first surgery. Adjuvant chemotherapy was given (Ifosfamide 120 mg/m2 and Doxorubicin 20 mg/m2 ), and she has been doing well for 12 months of follow-up.