The Welsh midfielder's reputation has continued to grow this season and he has been frequently linked with a move to Real Madrid, and Villas-Boas believes that Bale should take note of the career path of the Bernabeu attacker.
Villas-Boas told reporters: "You can see similarities in each of the players. Both of them are extremely technical players, and extremely powerful and pacy.
"It's funny to see how both players compare. They grew up as strikers, but became wingers. Gareth was a left-back and moved to winger and now going to a more advanced role. Ronaldo is also able to play that role up front.
"Ronaldo is now 28, and has achieved so much in his career, he is an example to Gareth as to what he can achieve."
Bale has scored 11 goals in 21 appearances in the Premier League this season.