A 72-year-old man was diagnosed with advanced rectal cancer possibly involving the prostate on magnetic resonance imaging (MRI) findings. Following neoadjuvant chemoradiotherapy (CRT), he underwent curative surgery. Confirming negative surgical margin through intraoperative pathological evaluation, colorectectomy with partial prostatectomy was performed in the jack-knife position. No evidence of local recurrence of the tumor was observed one year after surgery without symptoms of the urinary tract. Partial prostatectomy is a choice to be taken into account in the treatment of advanced rectal cancer achieving both the good surgical outcome and the patient's quality of life (QOL).