Mario Nigro was born in Pistoia, Italy on June 28, 1917. In 1929, Nigro's family moved to Livorno where, in 1933, aged sixteen, he taught himself to paint. Meanwhile, his education took a decidedly scientific turn: in 1941 he graduated in chemistry from the University of Pisa, and in 1947 he completed a second degree in pharmacy. In 1946 and 1947 he developed a non-objective style of painting, and soon created an original version of abstraction influenced by his scientific background.

In 1949 he had his first solo exhibition at the Libreria Salto in Milan, where he met Lucio Fontana and the Milanese movement known as MAC Movimento Arte Concreta. With his Ritmi continui simultanei (Continuous Simultaneous Rhythms) and Pannelli a scacchi (Chequered Panels) series, the artist progressed beyond the canons of Concrete Art. Towards the end of 1952 Nigro painted the first works of what would become the Spazio totale (Total Space) series, which he carefully theorized in a series of writings published in 1954 and 1955. In 1956 a powerfully expressive and dramatic tension developed in Nigro’s work, which generated the Tensioni reticolari (Reticular Tensions) series and, at the end of the decade, prompted him to adopt a style close to that of Art Informel.

In 1958 he resigned from his post as a pharmacist and moved to Milan to devote himself entirely to painting. In 1959, he had three solo exhibitions: at the Galerie Kasper, Lausanne, at the Galleria del Cavallino, Venice, and at the Galleria Annunciata, Milan. A year later the severe injuries caused by a car crash prevented him from painting for an extended period of time. Between 1965 and 1975 Nigro started to create environmental works, which he also exhibited at the 1968 Venice Biennale. From the mid-1970s onwards, he began his investigation of what he described as "the elementary geometric concept of the metaphysics of color," followed by his "Analysis of the Line". In 1983, his interrupted lines were sensitized through their transformation into a series of dots, giving rise to the subsequent Orizzonte (Horizon) and Orme (Tracks) series. In 1984 the City of Pistoia devoted a large retrospective exhibition to the artist. Mario Nigro died in Livorno on August 11, 1992.