He was born in 1916 in Constantinople (today Istanbul, Turkey). His family moved to France in 1922 because of the nationalist regime of Atatürk and its constant persecutions. This adventure left a deep scar on him. His choices were not derived from systematic painting studies, but by an early familiarity with art and literature, through his family. He was soon associated with the surrealist circles and the french intelligentsia in general.
His first solo exhibition was held in Paris (Billiet-Pierre Vorms gallery, 1938) with apparent surrealist influences. After the 2nd World War, his painting will be more involved in the atmosphere of the new Ecole de Paris. From 1948 to 1976, he was regularly organizing exhibitions at the Galerie de France.
In 1949 he acquired the French citizenship and in 1951 he settled in Provence. There he engaged in tapestry design and started to paint the surrounding hills from nature, using a particular style with overlapping lines and patches. This central section of his work includes the Spetses island landscapes, which he drew during his first trip to Greece in 1958.
In the field of portraiture, his most important works (after 1962) are peculiar portraits of his family members or other personalities, sometimes attributed with colour patches in an abstract manner, and sometimes attributed through distorting interventions or symbolic references on the drawing, as personal comments on the depicted person.
His last painting sections were the Turkish landscapes (1970-1981), the Trees (after 1980) and the Peintures du Supplice, for the Chapel Notre Dame de Pitié in Saint-Remy-de-Provence.
He cooperated with Gallimard editions and illustrated numerous books. He also designed the sets for significant theatrical performances. He created more than 150 tapestries and many sculptures.
He wrote essays on art and published the books Les Pretextats (1973) and La Colline tatouée (1983).
He was honored with the titles: Chevalier des Arts et des Lettres (1961), Chevalier de la Légion d'Honneur (1966) and Officier des Arts et des Lettres (1981).
His solo exhibitions have been held in almost every European country and the U.S.A. After his first solo exhibition in Athens (Merlin gallery, 1966) he regularly presented his work in Greece. His work was presented in numerous group and international exhibitions, as well as several retrospective ones in France, Belgium and Greece, before and after his death (Eygalières, S. France, 1985).
Since 1986, ‘Donation Mario Prassinos’ collection of 108 works, donated by the artist to the french state (1985) is housed at Saint-Remy-de-Provence.
In 2005, a monograph on his work was published (Actes Sud, Arles, France).