A 73-year-old female suffered spontaneous rupture of the extensor pollicis longus (EPL) and extensor pollicis brevis (EPB) tendons, for which she presented for treatment three to four weeks later. At that time there was no active metacarpophalangeal (MCP) or interphalangeal (IP) extension, leading to severe functional impairment of her hand. Since both the EPL and the EPB tendons were ruptured, transfer of the extensor indicis proprius (EIP) tendon was carried out for the EPL and transfer of the accessory abductor pollicis longus (AAPL) was carried out for the EPB. After a three-month period of follow-up, the thumb motion was restored and the patient was able to resume all activities of daily living. Although concomitant spontaneous rupture of both the EPL and the EPB is rare, transfer of the EIP and the AAPL tendons, respectively, seems to be the treatment of choice for anatomic reconstruction of such injuries.