Marcos Mundstock was born in the city of Santa Fe on May 25, 1942. He was the son of Ashkenazi Jewish immigrants from Rava-Ruska, a city in the Galicia region, in Eastern Europe, currently belonging to Ukraine. The city was part of Poland after the First World War. Mundstock's parents emigrated to Argentina with Polish passports separately, and met in Santa Fé. When Marcos was 7 years old he moved to Buenos Aires with his parents and his older sister.
Since he was little, as he said in some interviews, Mundstock was exposed to different musical influences. At his house they listened to radio programs from the Italian community and thus he met several tenors such as Beniamino Gigli and Tito Schipa. Neapolitan songs and opera arias were his first approach to music. They also listened to Jewish programs with the voices of synagogue liturgical singers who had a very operatic voice, and which Marcos enjoyed with his father.
Upon finishing high school in Buenos Aires, he began his engineering career (which he would abandon in the third year) and studied voiceover at the Instituto Superior de Enseñanza Radiofónica (ISER). Simultaneously, he entered the Engineering choir, where he met Gerardo Masana and the future members of Les Luthiers.
After obtaining his announcer's license, he worked for a while at Radio Municipal. After Onganía's military coup in 1966, he was left without a job. Upon collecting the months he was owed, he bought a piano and began taking lessons, but his attempts to learn from it were unsuccessful. Music was a pending subject in his life. He then decided to continue only with his singing classes.
On October 2, 1967, the day of Les Luthiers' debut, he gave himself the pleasure of imitating the lyrical singers that he had admired as a child by performing a free version of Mattinata, by Leoncavallo. From then on, he would intervene in the ensemble's operatic parodies.
In Les Luthiers he was also able to channel his vocation for writing and humor. During the first years of the group he wrote almost entirely the scripts of the shows, the lyrics of many songs and the stories of Johann Sebastian Mastropiero.
In parallel with Les Luthiers, he worked as a radio and television commercial announcer and also as an advertising copywriter. In 1974 he did the voice-over for the film Quebracho, by Ricardo Wullicher.
In the 90s he ventured into television. He played God and the Devil in several Tato Bores programs and made a memorable series of advertising films for the newspaper La Nación.
Between 2003 and 2005 he participated as an actor in four films: Roma, No sos vos, soy yo, Cama interior, and Torrente III. He also played a grotesque international criminal on the television show Mosca & Smith. In 2011 he appeared in "My First Wedding" by Ariel Winograd along with Daniel Rabinovich, where they both represented a funny duo of priest and rabbi.
He also participated in dubbing animated films. He voiced Auguste Gusteau in the Argentine version of Ratatouille (2007), and Joey in the Argentine and Latin American versions of Bolt. He also played Ermitaño in Metegol (2013), an animated film directed by Juan José Campanella.
On November 18, 2007, Les Luthiers celebrated its 40th anniversary with a recital titled Forty Years of Trajectory, with free admission, at Parque San Benito, located at the intersection of Figueroa Alcorta and La Pampa avenues, in the Federal Capital. Les Luthiers was able to gather more than 120,000 spectators.
He returned to television acting in 2007, as a guest actor in the series Los Cuentos de Fontanarosa (TV Pública). Later he was host of Al Colón (TV Pública, 2006/2008) and presenter of Pasado de copas (Argentine version of Drunk History, which aired in 2018 on Telefé).
In 2019 he returned to the cinema with the most important role, perhaps, of his career as an actor; He was the protagonist of The Tale of Weasels, by Juan José Campanella, along with Graciela Borges, Oscar Martínez and Luis Brandoni. In that film he played the frustrated screenwriter Martín Saravia.
Among the awards that the group Les Luthiers has received throughout their career are the Max Prize for Performing Arts (2001), awarded by the SGAE, the Latin Grammy for musical excellence (2011), the Princess of Asturias Award for Communication, the Spanish Government has also granted them the Commandery of the Order of Isabel la Católica (2007) and, in 2012, Spanish nationality by letter of nature. Also in 2007 they were distinguished as illustrious citizens of the city of Buenos Aires.
In January 2020, he announced his temporary withdrawal from the stage due to medical advice due to a health problem that he had been suffering from since 2019.7 He finally died at the age of seventy-seven on April 22 of the same year in Buenos Aires.