Arismendi was born on May 30, 1949, as the daughter of Rodney Arismendi, a historic leader of the Communist Party and founder of the Broad Front, and Rosa Dubinsky.
In the early years of her adolescence she joined the Union of Communist Youth and the Committee of Support to the Cuban Revolution "Camilo Cienfuegos".
In 1990, she was elected member of the Central Committee of the Communist Party for its XXII Congress. She joined the Collective General Secretariat in 1992, and until 2006 she served as General Secretary of the party, after the resignation of Jaime Pérez. She was part of the Broad Front Political Board between 1992 and 1999.