Maurice John Nicolaas Frohn qualified in medicine MB, BS from London University in 1956, passing the conjoint examination that same year. After house appointments at the Royal Sheffield Hospital and Children’s Hospital in Sheffield, he worked at the London Hospital Medical College as a lecturer in surgery and at St Mark’s Hospital as a senior surgical registrar. Passing the fellowship of the college in 1965, he worked as a consultant surgeon at the Benenden Hospital Trust and for the Post Office and Civil Service Sanatorium Society. He contributed articles on vagotomy and the cannulation of umbilical vein to the medical literature. In 1995, by then retired, he was involved in setting up a charity called *The Chernobyl Children’s Trust * to support the children whose parents were affected by the explosion of the reactor at Chernobyl nuclear power station in Ukraine in 1986. A report issued in 1991 apparently established that there had been no major effects of the radiation on the population. Visiting in 1996 Maurice found that this was by no means the case and that only 1% of the children born in the area to parents exposed to radiation had no health defects. He found the highest levels of thyroid cancer in children in the world. In three visits to the area during the late 1990s he treated many children and worked hard to set up channels whereby much needed drugs and expertise could be sent to the area. His work was profiled in an article written by John Carey in the *Weekend Telegraph*. He died on 24 November 2019, aged 89.