A friend and compatriot of Tristan Tzara, he was among the founders of the Dadaist movement at Cabaret Voltaire in Zurich. In 1922 he returned to Romania and worked as an architect and painter until 1941 when, in face of growing anti-semitism during World War II, he emigrated to the Land of Israel.
In 1953 Janco established the now famous Ein Hod artist village. In the last years of his life he helped create a Dadaist museum that houses an impressive collection of Dadaist art. The museum is named for him, Janco Dada Museum.
He died in 1984 in Tel Aviv.