We report herein a patient with a urethral calculus associated with urethral diverticulum. A 39-year-old man presented with scrotal swelling and acute retention of urine. Computed tomography of the pelvis and cystoscopy demonstrated a giant calculus in the proximal penile urethra. Emergency in-situ lithotripsy was performed. Complete stone clearance was achieved and a large urethral diverticulum was encountered. The rare occurrence of urethral diverticulum and associated stone disease were discussed.