He studied at the Paris Conservatoire, where his teachers included Ambroise Thomas for composition, Antoine Marmontel for piano, and François Benoist for organ.
He quickly built a reputation as a virtuoso and toured with, among others, the violinists Delphin Alard and Pablo de Sarasate.
His recordings are said to show the best aspects of the 19th-century French piano school: clarity, point, and control in rapid, detaché passages and limpid pianissimo scales.
[1] They also give evidence to comments made by his pupil Lazare Lévy, who himself would become an influence on the French musical scene.
Lévy wrote: "The astonishing precision of [Diémer's] playing, his legendary trills, the sobriety of his style, made him the excellent pianist we all admired".