Cristal's appeared in a number of films in Argentina and Mexico before taking on her first English-language role as Margarita in the 1956 Western film Comanche. Following her Golden Globe Award for New Star of the Year in The Perfect Furlough (1958), Cristal went on to roles in Cry Tough (1959), Legions of the Nile (1959), The Pharaohs' Woman (1960), and was asked by John Wayne to play the part of Flaca in his epic The Alamo (1960). In 1961 she had a key role in the western Two Rode Together.