Capsaicin is the main pungent component of chili peppers. This is the first case, to our knowledge, that describes prostate-specific antigen (PSA) stabilization in a patient with prostate cancer, who had biochemical failure after radiation therapy. A 66-year-old male underwent radiotherapy treatment for a T2b, Gleason 7 (3+4) adenocarcinoma of the prostate, with a PSA level of 13.3 ng/mL in April 2001. He had 3-dimensional conformal radiotherapy of 46 Gy in 23 fractions to the prostate and pelvis, and a prostate boost of 30 Gy in 15 fractions. Radiotherapy was completed in May 2001 and PSA nadired in January 2002 (0.57). Due to the continued PSA rise, the patient was started on bicalutamide (50 mg orally, daily) and leuprolide acetate (1 dose of 22.5 mg intramuscularly) in July 2005 when PSA was 38.5 ng/mL. Due to poor tolerance of androgen ablation therapy, the patient discontinued treatment and started taking 2.5 mL of habaneros chili sauce, containing capsaicin, 1 to 2 times a week in April 2006. Prostate-specific antigen doubling time (PSAdt) increased from 4 weeks before capsaicin to 7.3 months by October 2006. From October 2006 until November 2007, the patient remained on capsaicin (2.5 to 15 mL daily) and his PSA was stable (between 11 to 14 ng/mL). By January 2008, his PSA rose to 22.3 and he has maintained a PSAdt between 4 and 5 months, where it presently remains. Due to the patient's continued PSA rise, he was restarted on bicalutamide (12.5 mg daily). Apart from PSA relapse, the patient remains free of signs or symptoms of recurrence.