In addition to being a gynecologist and obstetrician, he was also a pioneer in the use of X-rays.
He had high-society patients: the Romanian princess Ileana Hohenzollern-Sigmaringen, Ivy Lowe, the English Jewish wife of the Soviet Foreign Minister Maxim Litvinov, and members of the Rothschild family.
In 1930 following a trip to Paris, Warnekros took on Einar Wegener as a patient, and arranged a series of operation that transformed Wegener into Lili Elvenes (Elbe). This was separate from the similar operations performed at Magnus Hirschfeld's Institut für Sexualwissenschaft. This resulted in newspaper headlines.
++In February 1931, Warnekros was interviewed by Copenhagen's Dr Rank for the Ekstar Baldet newspaper. He boasted that he had performed an unprecedented operation that the top French doctors were incapable of. There is no mention of the earlier trans women who had been operated on under the aegis of Magnus Hirschfeld.
However Lili died during a follow-up operation later that year (this is in contrast to Hirshfeld's transsexual patients who survived).
In 1933 Warnekros joined the Nazi party. In 1936 he was accused of being a Jew-lover because of his work with the Rothschilds. However he was able to keep treating Jewish patients until 1944, partly because he also treated the wife of Nazi Party leader in Saxony. In addition he also did involuntary sterilizations. In 1944, he helped Eva Olbricht, whose husband had been involved in the Stauffenberg plot against Hitler, to escape from Dresden.
The clinic was destroyed in the February 1945 air raids and subsequent firestorm of Dresden.
Warnekros remained head of the clinic until 1948, when Baroness von Goldschmidt-Rothschild invited him to live in Paris.
++He died at the age of 67.
- Dr. Rank: "Manden, der blev Kvinde. Professor von Warnekros fortæller: Lili Elbe blev til ved et i Lægevidenskabens Annaler enestaaende Indgreb“"(The man, who was female. Professor von Warnekros says: Lili Elbe results from an intervention unique in the annals of medical science). Ekstra Bladet. 28.02.1931, 1, 9.
- Susanne Kailitz. "Das Experiment: 1930 führte der Dresdner Gynäkologe Kurt Warnekros eine der weltweit ersten Geschlechtsumwandlungen durch". Zeit Online, 13. Januar 2012. www.zeit.de/2012/03/S-Geschlechtsumwandlung,