See his autobiography (1973).
Aside from his early and singular fascination with the piano, another interesting childhood trait is that Rubinstein didn't begin speaking until some time around the age of three. Until the time that he developed speech, Rubinstein would entertain his family by imitating non-speech sounds. The descriptions of Rubinstein's delayed speech, his early childhood tantrums and his later virtuosity closely follow a similar pattern of development of other famous late-talkers, such as fellow pianist Clara Schumann and physicist (and sometimes-musician) Albert Einstein, among others. Beginning at the piano when he was still two years of age, Rubinstein first studied in Warsaw. At the age of four he played for the great German violinist Joseph Joachim who was greatly impressed and began to play the role of mentor for the young prodigy. By age ten Rubinstein moved to Berlin to continue his studies. In 1900, at the age of thirteen, he made his debut with the Berlin Philharmonic, followed by appearances in Germany and Poland and further study with Karl Heinrich Barth. In 1904, he moved to Paris to launch his career in earnest. There he met the composers Maurice Ravel, Paul Dukas, and the violinist Jacques Thibaud. He also played Camille Saint-Saëns' Piano Concerto No. 2 in the presence of the composer. Through the family of Juliusz Wertheim (to whose understanding of Chopin's genius he attributed his own inspiration in the works of that composer) he formed a friendship with the violinist Paweł Kochański, which led later to artistic and social involvement with Karol Szymanowski.
Rubinstein made his New York debut at Carnegie Hall in 1906, and thereafter toured the United States, Austria, Italy, and Russia. According to his own testimony and that of his son in François Reichenbach's film L'Amour de la vie (1969), however, he was not well received in the United States, and in 1907, when he found himself destitute and desperate in a Berlin hotel room, hounded by creditors and threatened with being thrown out into the street, he tried to hang himself, but failed, and then felt "reborn" with a great love of life. In 1912, he made his London debut, and was frequently in London until 1914 in the musical salon of Paul and Muriel Draper, in company with Kochanski, Stravinsky, Jacques Thibaud, Pablo Casals, Pierre Monteux and others.
During World War I Rubinstein lived mainly in London, accompanying the violinist Eugène Ysaÿe. From 1916 to 1917, he toured Spain and South America, developing an enthusiasm for the music of Enrique Granados, Isaac Albéniz, Manuel de Falla, and Heitor Villa-Lobos. He was the dedicatee of Villa-Lobos's Rudepoêma and Stravinsky's Trois mouvements de Petrouchka.
After 1914 Rubinstein never again played in Germany. In 1917, Rubinstein left Cádiz, Spain with his music manager Ernesto de Quesada, on the Infanta Isabel to South America. He debuted on July 2, 1917 in the Teatro Odéon, in Buenos Aires. This tour included concerts in Buenos Aires, Montevideo,Uruguay, Santiago de Chile and Valparaíso, Chile.
In 1921 he made two American tours, travelling to New York with Paweł Kochański (who remained his lifelong friend) and Karol Szymanowski. The autumn voyage was the occasion of Kochański's permanent migration to the USA.
Rubinstein made numerous live-recording player piano music rolls for the Aeolian Duo-Art system and the American Piano Company (AMPICO), all of which survive today and can be heard. In 1932, he withdrew from concert life for several months to work on his technique and repertoire. Astor Piazzolla cites a Rubinstein concert staged in Buenos Aires in 1939 as one of his first great impressions, which led the 18-year-old to write and dedicate to Rubinstein a piano "concerto", a definition that Rubinstein was to debate with the young composer.
During World War II, the Germans looted his home in Paris, and his career became centered in the United States. Impresario Sol Hurok insisted Rubinstein be billed as Artur for his American concerts, even though the pianist referred to himself as Arthur when in English speaking countries. He became a naturalized citizen in 1946. He refused to play in post-war Germany because of the Nazi extermination of most of his family. While never becoming an observant Jew, he was a passionate supporter of Israel. He retired from the stage in 1976, as his eyesight and hearing were rapidly deteriorating. He became almost blind in later life.
Although best known as a recitalist and concerto soloist, Rubinstein was also considered an outstanding chamber musician, partnering with such luminaries as Henryk Szeryng, Jascha Heifetz, Gregor Piatigorsky, and the Guarneri Quartet. Of the piano solo repertoire Rubinstein recorded a vast portion, including innumerable Romantic composers. He recorded nearly all the works of Chopin. He was one of the earliest champions of the Spanish and South American composers and of French composers who, in the early 20th century, were still considered "modern" such as Debussy and Dukas. In addition, Rubinstein was the first champion of the music of his compatriot Karol Szymanowski. Rubinstein, in conversation with Alexander Scriabin, named Brahms as his favorite composer, a response that enraged Scriabin.
Rubinstein was fluent in eight languages. His photographic memory of much of the repertoire, not simply that of the piano, was formidable. According to his memoirs, the pianist learned César Franck’s Symphonic Variations while on a train en route to the concert, without the benefit of a piano.
Rubinstein also fathered a daughter with a South American woman.
During his marriage, Rubinstein carried on a series of affairs with other women, including Mary Irene Curzon, and in 1977, at age 90, he left his wife for the young Annabelle Whitestone, though he and Nela never divorced.
In 1977, he was made an honorary Knight Commander of the Order of the British Empire (KBE).