In 1929, Prince Mahidol decided to work at McCormick Missionary Hospital in Chiang Mai, having found that Siriraj Hospital could not arrange for him to work as a resident doctor as he wished. He worked devotedly for just 24 days in Chiang Mai, but left cherished memories of "The Prince Doctor" firmly in the minds of everyone. He returned to Bangkok to attend the royal cremation ceremony for His Royal Highness Prince Bhanubhand, a senior royal, on May 18, with the intention of bringing the family to live together in Chiang Mai where he had acquired a comfortable home as residence. He fell seriously ill, however, and could not travel anywhere again after that. He died on 24 September 1929.