She starred in movies, musicals, as well as in several Peruvian telenovelas, including Torbellino, Carmín, Simplemente María, Asi es la vida, and Al fondo hay sitio.

However, due to problems and the delinquency of her own representative, her cast (including herself) was stranded in Buenos Aires, where she was eventually convinced to go live in Peru.

Initially, Trejos worked as a model for contests in humorous sketches, sharing the set with characters such as Tulio Loza; she was also an actress in radionovelas.

Then in 1969, Trejos landed one of the main characters in the channel's new proposal, Simplemente María, a resoundingly successful telenovela on the South American continent, which increased her celebrity status.

Three years later she participated in her second film, La fuga del Chacal, which was a box office success in Peru.