He applied to join the Akademie der bildenden Künste but failed to secure a place, and spent some time working at his uncle's bronze foundry in Vienna.

He made the monument "June Victims" for his home city of Osijek in 1928, commemorating the murders of Pavle Radić, Đuro Basariček, and Stjepan Radić in Belgrade in 1928; all three were Croatian members of the Yugoslav Parliament who were fatally shot in the debating chamber by a Montenegrin Serb, Puniša Račić.

[4] He staged a one-man exhibition of portrait heads at the Académie, including his Freud and a bust of Paul-Henri Spaak.

He made portraits of King Albert I, Queen Astrid of the Belgians, Emile Vandervelde and August Vermeylen, and also exhibited at the Galerie Monteau in December 1934 and January 1939.

Concerned by the approaching threat of Nazi Germany, he escaped to England in 1938, a year before the outbreak of World War II.

He made portraits of the members of British Royal Family, including Elizabeth II, the Duke of Edinburgh, the Queen Mother, and the Earl Mountbatten of Burma, at a studio in St James's Palace.

His last major piece, a monumental memorial to the Royal Canadian Air Force in Toronto, was unveiled by Queen Elizabeth II in 1984.

Meanwhile, in the 1940s and 1950s, he also created a series of lesser-known relief works, which he called "Les Fleurs de mon Coeur" (The Flowers of my Heart).

Nemon's technique depended on modelling from life directly in clay, quickly making many small studies with no preliminary drawings.