Samazeuilh began his career by taking a law degree, but then turned his attention to music and studied with Chausson, d'Indy and Bordes at the Schola Cantorum, and with Paul Dukas. Although born in Bordeaux, he had a house at Ciboure, and became a friend of Ravel on his summer holidays. His own music reflected the early styles of Ravel and Debussy. He claimed that a theme from one of his own works, Naïades au soir, was adopted almost unchanged by Ravel for the theme of the Nymphs in Daphnis et Chloe.
Samazeuilh's musical output was small, and consisted mainly of vocal and instrumental works. He was better known as a critic and translator. He translated Tristan & Isolde into French, wrote a study of Paul Dukas (1913), and published a volume of his musical memoirs: Musiciens de mon temps: chroniques et souvenirs, (Paris, M.Daubin, ).