He debuted in theater at the age of eleven, participating at plays on the Teatro Liceo, under the supervision of playwright Luisa Vehil.

After taking a rest from filming in 1967, de Rosa returned to the screens in 1968, participating in the Italian-Spaniard production Il marchio di Kriminal.

De Rosa began 1973 by making another movie, then established himself in West Germany for a small period, having been contracted by an important television network to participate in a sitcom.

In 1974, de Rosa made seven more movies, including Yo la vi Primero, El Reprimido, and Los Nuevos Españoles, which were released in English as I Saw Her First, The Repressed Man, and The New Spaniards, respectively.

In 1975, de Rosa acted in the international hit, El Poder del Deseo (Power of Desire).

In 1978, de Rosa participated in El Juego del Diablo (Devil's Game), after which he decided to take a voluntary retirement from Argentine screens.

Then, he began 1988 with Los Pilotos mas locos del mundo (The Craziest Pilots in the World, a sequel to Los Bañeros más locos del mundo), which was followed by Soldadito Español (Little Spaniard Soldier), a comedy movie that was directed by Antonio Gimenèz Rico).

Next came one of the most important acting jobs in Fernandez de Rosa's career: His character in Grande Pa!, Teo, became very popular in Argentina.

He also participated in "Una Mujer Bajo la Lluvia' ("Woman in the Rain") as "Javier", and in Aqui, el que no Corre...Vuela (Here, He Who Won't Run...Will Fly).

Fernandez de Rosa acted along with the performers he cast for the children's telenovela, including Maria Jimena Piccolo, Facundo Arana, Romina Yan (Morena's daughter) and, as aforementioned, Agustina Cherri.

The fact that Fernandez de Rosa had lived for many years in Spain helped him play "Saverio", who had a Spaniard accent.

When "Chiquititas" began to be shown in the United States on Telefe's satellite network during the 2000s (decade), Fernandez de Rosa started to become famous among Hispanics in that country as well.

Fernandez de Rosa slowed down his work as a screen actor considerably after "Chiquititas", concentrating more on his job as casting director for Telefe.

Already a veteran actor, Fernandez de Rosa once again participated in only one new production in 1997, "24 Horas (Algo Esta por Explotar)" ("24 Hours, Something's About to Explode") a drama-comedy starring Julieta Ortega and Eduardo Cutuli.

In "24 Horas (Algo Esta por Explotar)", Fernandez de Rosa also had the opportunity to act alongside well known actress Divina Gloria.

Fernandez de Rosa took 1998 off, then returned to Argentine television in the 1999 soap opera, "La Mujer del Presidente" ("The President's Wife").

2001 has so far proven to be the last year in which Fernandez de Rosa did screen acting, with his last appearance in a film named "Te Besare Mañana" ("I Will Kiss you Tomorrow").