Born in Hong Kong, Woo qualified from the Middlesex Hospital in 1913. He was particularly interested in gynaecology, and was house surgeon and assistant to Victor Bonney at the Middlesex and at the Chelsea Hospital for Women. During this time he designed the Reverdin-Woo needle. He served in a military hospital in England during the first world war, and then went with a Rockefeller scholarship to New York and Baltimore, where he worked with Howard Kelly and came under the influence of W S Halsted. He also met the future head of the department of gynaecology of the Peking Union Medical College, Preston Maxwell, whose first assistant he became. Early in the 1920s the PUMC had been rebuilt by the China Medical Board of the Rockefeller Foundation. In Arthur Woo's own department Maxwell, Miles, and he worked on osteomalacia. They showed that, as had previously been suspected, osteomalacia was a de-ficiency disease related to rickets. When he returned to Hong Kong he established a clinic and organised the Babington Hospital, which became the centre of his large practice. His interests included opium addiction, leprosy, and cancer. Many distinctions came to him; the one that pleased him most was the Fellowship of the Royal College of Surgeons, awarded through his old teacher Lord Webb-Johnson. He was an Honorary Fellow of the International College of Surgeons, Honorary Visiting Professor at Lin Nam University, and consultant to the Cancer Clinic in Macao. He lectured in gynaecology and obstetrics and was an internal examiner at Hong Kong University. In his last illness he returned to the Middlesex Hospital for treatment. Woo lived at 55 Conduit Road, Hong Kong, and died in February 1964, aged 77, survived by his wife, with their son and five daughters. His humour, courage and faith lasted to the end.