Born on Nov 3rd 1897 Tranquebar, Tharagambadi a town in Thajavur district, Tamil Nadu to Thiru Ayyavu Rathinam , a postmaster in Tranquebar. He studied in Tranquebar till 8th class and went on to Singapore for higher studies. He  obtained a scholarship to complete his studies in Malay and attained Licentiate in Medicine and Surgery LMS degree from King Edward VII college of Medicine in the year 1923.He obtained this scholarship from the government since he consistently did very well in his school. He later joined Singapore General Hospital. He came to India in 1928 and married Thirum. Saraswathy in March 26 ,1928. In 1936 he was transferred to Penang Hospital as Assistant Surgeon. After  the British personnel were evacuated from the island, he took over as the head of the surgical unit till 1945.After the war he was promoted to Surgeon, Malayan Medical Service. At this time when the war broke out, he sensed it was not safe for his family, so he sent them back to India via the sea and he stayed back to carry on with his duties. His wife and children reached Nagapattinam on May 3rd 1941.During the war, the family did not hear from Dr.Apparajoo. They did not know whether he was dead or alive. Once the war was over, they heard their Father's voice via an announcement and he contacted via a telegram intimating that he was alive. When the war was over he took leave and came to Calcutta via a submarine and travelled to Thanjavur to see his family for the first time in 4 years. His daughters still remember the sight of him standing with arms wide open.He went back to Penang and worked in the hospital. He helped many people and saved many lives during the war. He was awarded OBE medal (Order of the British Empire) from the British government after the World War II for his service in saving countless lives of civilians and injured victims on 19 July 1949.He took voluntary retirement in July 1949 to come back to Thanjavur,  to his family. "He was a great person, a caring, loving Father and a great Surgeon. He was humble, simple , kind and a disciplined person. He was generally helpful to anyone in need, especially poor people.He started a trust for Indian children in Singapore for a girl and a boy to get scholarship in High school in the Singapore Education department in the name of Raju Pillay.He loved gardening, music and playing Tennis.After his retirement, he became the Honorary Magistrate in Thanjavur .He also worked hard to develop schools and supported them with resources and time. He loved to spend his time amidst his grandchildren during his retired life. " - His daughter's account of her father ,Dr.Apparajoo.

The Penang Free School to this day provides scholarships to young children in the name of Dr.Apparajoo Scholarship honoring his service.