He is best known for having created the "Gidget" novels, which inspired a series of movies, two television series, three telemovies and a feature length animated film. He based the title character on his own daughter, Kathy Kohner-Zuckerman.
Having studied in Vienna and Paris, Kohner wrote his thesis titled "Film ist Dichtung", meaning "Film is Poetry". Subsequently, he worked as a journalist in Prague and Berlin. For a short while in 1929/1930 he was employed as a movie correspondent for German newspapers in Hollywood. He used his stint there for a minute role in Lewis Milestones legendary anti-war movie All Quiet on the Western Front.
Back in Berlin in 1930, Kohner began to work for the German film industry for real, starting with the comedy Seitensprünge - a production a young Billy Wilder also happened to be working on as a screenwrite - where he himself was assistant producer to István Székély. In 1932/33 Kohner supplied a full three movies of his brother's, Universal producer Paul Kohner, with screenplays, often in cooperation with other authors. Having been Jewish, he was pushed into isolation due to the ongoing worsening of the political climate. In 1934, Robert Siodmak, the executive producer of his last German film Brennendes Geheimnis who had fled to Paris in the meantime, made it possible for him to contribute to the screenplay for the French piece La crise est finie. During the time of the National Socialism Friedrich Kohner only contributed (uncredited) to the screenplay Viktoria, an adaption of a novel by Knut Hamsun. In July 1936, together with his wife Fritzi and their four-year-old daughter Ruth, Friedrich Kohner finally managed to emigrate to the US. From the time he established himself in Hollywood (mostly uncredited work for developing screenplays and treatments), he went by the Americanized name of Frederick Kohner. For his contribution to the story for the 1938 Deanna Durbin comedy Mad About Music, Kohner received an Oscar nomination the following year. Subsequently, from 1939 onward, he sporadically was given the odd offer to create ragular screen plays for movies again, among them being The Men in Her Life with Loretta Young and Conrad Veidt. The bulk of his work in the US however continued to be concentrated on developing stories for films.