Samuel Stening was the third of five children of George Smith Stening and Muriel Grafton Lees. Of these five children the four boys became prominent Sydney doctors (Sir George and Malcolm obstetricians and Warwick an orthopaedic surgeon) and the sister married a doctor. The father was a graduate of the Hawkesbury Agricultural College, a consultant in dairy procedures and an original member of the Milk Board. The maternal grandfather, Samuel Edward Lees, was a publisher and Lord Mayor of Sydney. He gave the gavel he used as Lord Mayor to the grandson named after him, who in turn gave it to the Australian Paediatric Association when he was president of that body.

Stening attended Sydney Boys' High School and while there was a champion swimmer. Surfing at Bondi was also a great love. Residencies at the Royal Prince Alfred, Royal North Shore and Royal Alexandra Hospital for Children followed graduation and then he went to England for further paediatric experience and obtained the diploma in child health. He returned to Australia, entered general practice at Bondi, was appointed to the honorary staff of the Royal Alexandra Hospital for Children and became a member of the College by examination all in 1938.

On the outbreak of war he joined the Royal Australian Navy and had active service at sea from 1940 to 1942, twice serving on ships when they were sunk, the Waterhen in the Mediterranean and the Perth in the battle of the Sunda Strait. There he became a prisoner of the Japanese and spent the rest of the war in Japan. Having attained the rank of surgeon lieutenant commander, he was commanding officer and senior medical officer of the prison camp. In 1945 he was awarded the Distinguished Service Cross and wrote a report on the care of prisoners by the Japanese that was highly regarded by the Navy Board. In 1945 he began specialist practice as a paediatric physician in Macquarie Street. He steadily climbed the ladder of seniority at the Children's Hospital, becoming a senior physician, chairman of the medical board and a member of the board of management before reaching retirement in 1968. As a junior he started an allergy clinic at the hospital and this remained a strong interest throughout his medical career, but not to the exclusion of general paediatrics.

In 1947 he was appointed senior paediatrician at the Women's Hospital, Crown Street, and work with neonates became his greatest love. All the papers he presented at meetings of the Australian Paediatric Association (now the Australian College of Paediatrics) dealt with the newborn. Late in his career the nursery at Crown Street Hospital was named the Sam Stening Nursery in his honour. He was very sad when the Government closed this hospital and his beloved nursery disappeared. From 1951 he was consultant paediatrician at St Lukes Hospital. In 1941 he married Olive Thompson whose engineer father had made the first steam car in Australia. Her artistic interests made their home in Bellevue Hill a very pleasant refuge, with the scent of freesias coming in the open windows, a few splendid heads sculpted by Olivia standing round and some striking modern paintings decorated the walls. A large Charles Reddington dominated the dining room, the rich pigment tumbling down in generous profusion. They had one daughter and three grand children.

Sam was a quick and competent worker. He seemed to make decisions quickly and without too much effort and his opinion was usually respected. He was a pleasant colleague, inclined to do his work with skill and without interfering with others. In some respects he was a conservative, comfortable with the status quo in the organisations he served, but very ready to be up with new advances as they influenced his work. Thus he would have been happy for the Australian Paediatric Association, of which he was president from 1968 to 1969, to remain a small, cosy, selective group rather than expanding to include all paediatric interests. He was happy for his hospital to retain the honorary system rather than appointing staff specialists to press forward the rapidly advancing frontiers of paediatrics.

He was a foundation member of the Australian Association of Allergists, consulting paediatrician to the Repatriation Department and to Sydney Legacy and a member of the Editorial Board of Modern Medicine of Australia. He lectured in neonatal paediatrics at the University of Sydney and examined in paediatrics in the College Fellowship examination. He was chairman of the Consultative Council for the Physically Handicapped, an advisory body of the NSW Health Department and a member of the research committee of the Children's Medical Research Foundation. His early enthusiasm for swimming and surfing gave way to a lasting enthusiasm for fishing and he eagerly looked forward to holidays and weekends at Sussex Inlet, however he was a kindhearted fellow all his life and in later years threw back all the fish he caught.