Born in Santiago de Chile, she worked at La Moneda Palace with Salvador Allende. After the death of her partner, Miguel Enriquez, at the hands of the military, Carmen Castillo, who was pregnant and injured, was expelled from Chile and came to France as a political refugee.

She has directed numerous documentaries for television, especially for the French channels TF1 and FR3 and for the Franco-German Arte. The first was Los muros de Santiago (1983), which was followed by Estado de guerra: Nicaragua (1984). La Flaca Alejandra (1993) won the Golden FIPA at Cannes, in addition to other awards in Geneva, Monte Carlo, San Francisco and New York.