Andrésen's role was as Tadzio, the Polish boy with whom the film's older protagonist Gustav von Aschenbach (played by Dirk Bogarde) becomes obsessed.

Following the Cannes Film Festival a year after the premiere of Death in Venice, Andrésen received international headlines as "the most beautiful boy in the world".

[2] Andrésen later described his discomfort with his role in Death in Venice and its director Luchino Visconti, stating that "When I watch it now, I see how that son of a bitch sexualized me.

After the release of Death in Venice, Andrésen spent an extended period of time in Japan and appeared in a number of television commercials and also recorded several pop songs.

In addition to being an actor, Andrésen is a professional musician, and (as of 2006) until recently performed and toured regularly with the Sven Erics dance band.

[10][11] In 2021 Andrésen was the focus of The Most Beautiful Boy in the World, a documentary detailing his experiences post-fame after the premiere of Death in Venice.

[13][14] Andrésen and Roman had another child, a son named Elvin (1986–1986), who died of sudden infant death syndrome at 9 months of age.