The artist was born on May 17, 1924 in the city of Karlovac, Croatia. He studied at the Academy of Fine Art in Zagreb, graduating in 1950. He had his first institutional exhibition, with artist Miljenko Stančić, in 1952 at the Museum of Arts and Crafts in Zagreb.

Vaništa was a cofounder of the Gorgona Group, a renowned collective of Yugoslav artists and thinkers that worked from 1959 to 1966. Among its core members were painters Marijan Jevšovar, Đuro Seder, and Julije Knifer; sculptor Ivan Kožarić; critic Radoslav Putar; and architect Miljenko Horvat. The artist Dimitrije Bašičević Mangelos, became an active member of the group later on. 

Vaništa created a varied body of work: he produced everything from collages and traditional landscapes and still lifes to photographs and austere abstract paintings. He was a professor in the architecture department at the University of Zagreb and, in 1994, was made a full member of the Croatian Academy of Arts and Sciences. He exhibited his work a great deal throughout Croatia and had shows all over the world, in cities such as Paris, London, New York, Bombay, and Beijing. With the Gorgona Group, he participated in the 1997 Venice Biennale. A survey covering seventy years of Vaništa’s work, “Abolition of Retrospective” was mounted at the Museum of Contemporary Art, Zagreb in 2013.

He died on March 24, 2018 in the city of Zagreb, Croatia.