The 70-year-old Oscar-winner said playing a grand-father could be fun if the script is interesting, reported Contactmusic.
"That's just life. We can't play certain parts any more. We're playing the father or the grandfather or the great-grandfather and that can be written in a funny way, so it's fine," De Niro said.
"But you're not carrying the movie as the young romantic lead - those days are gone," he added.
The actor joked that he may go for younger roles if some technology can help people look young.