[3][4] He co-authored the fifth edition of Birch's Management and Medical Treatment of Children in India with Charles Robert Mortimer Green which was published by Thacker Spink & Co., in Calcutta in 1913.

The book was originally published by Henry Goodeve as Hints for the General Management of Children in India in the absence of Professional Advice (1844).

[5] His work in India was interrupted by the First World War in which he served as an officer in the Royal Army Medical Corps.

[3][6] After his return from war service, Green-Armytage was promoted to major in the IMS in 1919, and finally to lieutenant colonel in 1927 before retiring in 1933.

[4] On his return to England, Green-Armytage practised as a consulting gynaecologist and held appointments with the West London, British Postgraduate, Italian, and Tropical Diseases Hospitals.