Beginning in 1922, Casadesus collaborated with the composer Maurice Ravel on a project to create piano rolls of a number of his works.

In 1943, he performed as part of a series of New York concerts meant to raise money for the Coordinating Council of the French Relief Societies.

His pupils included Claude Helffer, Grant Johannesen, Olive Nelson Russell, Monique Haas, Mary Louise Boehm, Carol Lems-Dworkin, and William Eves, who appeared in the Casadesus-based Bell Telephone Hour fine arts documentary TV series "The First Family of the Piano" (1967) and was a longtime piano instructor at Bowdoin College.

In her later years she edited the works of Ravel for G. Schirmer, Inc. A product of the school of French pianism, his style of playing was classical and restrained with a very delicate approach to melody and line.

Among his other recordings are those of the complete piano music of Ravel (for which he was awarded the Grand Prix de l'Academie Charles Cros and the Grand Prix de l'Academie du Disque), and the Beethoven Violin Sonatas with Zino Francescatti (of which the Kreutzer Sonata was filmed and has been released on DVD).

Later, Casadesus made LP recordings of a number of Mozart's piano concertos with George Szell and the Cleveland Orchestra (sometimes billed as the Columbia Symphony for contractual reasons), including nos.

Casadesus was joined by his wife Gaby and their son Jean in recordings of Mozart's concertos for two and three pianos, accompanied by the Philadelphia Orchestra conducted by Eugene Ormandy.

He also made recordings of four of Bach's concertos for two and three keyboards, issued by Columbia, under the batons of Eugene Ormandy, Pierre Dervaux, and Edmond de Stoutz.

In addition, Casadesus' recorded output includes works by Scarlatti, Schubert, Schumann, and Chopin, as well as Manuel de Falla's Nights in the Gardens of Spain.