After the war, Brendel composed music, as well as continuing to play the piano and to paint. However, he never had any more formal piano lessons and although he attended masterclasses with Edwin Fischer and Eduard Steuermann, he is largely self-taught.
Brendel gave his first public recital in Graz at the age of 17. He called it "The Fugue In Piano Literature", and as well as fugal works by Johann Sebastian Bach, Johannes Brahms and Franz Liszt, it included some of Brendel's own compositions. However, he gave up composing shortly after this to concentrate on the piano. In 1949 he won 4th prize in the Ferruccio Busoni Piano Competition in Bolzano, Italy and moved to Vienna the following year. At the age of 21, he made his first record, Sergei Prokofiev's Piano Concerto No. 5. He went on to make a string of other records, including three complete sets of the Ludwig van Beethoven piano sonatas (one on Vox Records and two on Philips Records). He was the first performer to record the complete solo piano works of Beethoven. He has also recorded works by Liszt, Brahms (including Brahms' Concertos), Robert Schumann and Franz Schubert. Unlike virtually all classical pianists, he has recorded very little Chopin other than the Polonaises. An important collection of Alfred Brendel is the complete Mozart Piano Concertos recorded with Sir Neville Marriner and the Academy of Saint Martin in the Fields which is included in the Phillips 180 CD complete Mozart Edition.
Brendel recorded extensively for the Vox label -- particularly his first set of the Beethoven sonatas -- but secured a major recording contract only in the 1970s, nor did he play much outside Austria. His breakthrough came after a recital of Beethoven at the Queen Elizabeth Hall in London, the day after which three major record labels called his agent. Around the same time he moved to Hampstead, London, where he still resides. Since the 1970s, Brendel has recorded for Philips Classics Records.
Brendel has been married twice. His first marriage, from 1960 to 1972, was to Iris Heymann-Gonzala, and they had a daughter, Doris. In 1975, Brendel married Irene Semler, and the couple have three children; a son, Adrian, who is a cellist, and two daughters, Katharina and Sophie.
Critical reaction to Brendel’s playing has been mixed. While he has been lauded by Michael Steinberg as “the new Schnabel”, critic Harold C. Schonberg noted that some critics and specialists accused the pianist of “pedanticism.”. Brendel's playing is sometimes described as being "cerebral, and he has said that he believes the primary job of the pianist is to respect the composer's wishes without showing off himself, or adding his own spin on the music:
"I am responsible to the composer, and particularly to the piece".As well as his former mentor and teacher, Edwin Fischer, he cites Alfred Cortot, Wilhelm Kempff, and the conductors Bruno Walter and Wilhelm Furtwängler as particular influences.
In recent years, Brendel has worked with younger pianists such as Paul Lewis, Mark Gasser, Roberto Carnevale, Andrew von Oeyen and Till Fellner. He has also performed in concert and recorded with his son Adrian.
In November 2007, Brendel announced that he would retire from the concert platform after his scheduled concert of 18 December 2008 in Vienna, which is to feature him as soloist in the Piano Concerto No. 9 of Mozart.