Synchronous rectal and prostate malignancies are rare and standard treatment guidelines have not yet been established.1-3 Combined robotic rectal and prostate surgery represents a potentially excellent approach for managing synchronous rectal and prostate malignancies, offering the advantages of a minimally invasive procedure.4 METHODS: A 78-year-old male with a history of hypertension and type 2 diabetes presented with 3months of dyschezia and dysuria. Diagnostic colonoscopy revealed a submucosal mass 3cm from the anal verge in the anterior wall of the rectum, with abnormal carcinoembryonic antigen and prostate-specific antigen levels. Pelvic computed tomography (CT) indicated indistinct boundaries between the rectal mass and the prostate, suggesting potential invasion. CT-guided biopsies confirmed a rectal gastrointestinal stromal tumor (GIST) and prostatic acinar adenocarcinoma. After 3months of neoadjuvant therapy with imatinib mesylate and bicalutamide, significant tumor reduction was achieved.5 Subsequently, the patient underwent simultaneous robotic sphincter-preserving rectal resection and prostatectomy, starting with the prostatectomy, followed by rectal tumor excision and ending with bowel reconstruction and vesicourethral anastomosis using a running suture technique. The operation time was 220min and the estimated blood loss was 50mL. No surgical complications were encountered and all resected margins were free of tumor, indicating a complete excision. The patient recovered well and was discharged on the seventh postoperative day. Follow-up at 3months showed no evidence of recurrence or functional impairments. Simultaneous robotic sphincter-preserving local rectal resection and prostatectomy can be feasibly and safely performed following neoadjuvant therapy in cases of synchronous rectal GIST and prostate cancer.