Mederos founded several organizations including the School of Social Services at the University of Havana; the Foundation for Social Services, which developed programs for children's organizations in Cuba; "Of Human Rights" (New York City, 1961);[2] and a Cuban exile lobby that worked for the release of political prisoners.
She was the founding vice president of the National Association of Cuban American Women (NACAW).
[8] Representing Cuba, Mederos was a member of the first CIM conference which met in Havana in 1930.
[9] In September 1959, Mederos served for five months as first Minister of Social Work in Cuba,[5] under Fidel Castro's provisional government.
[10] She arrived in the US in 1961 with her daughter María Elena González Mederos, where she worked for UNICEF.