Carlo Ancelotti's Real will face La Liga champions and city rivals Atletico Madrid in the UEFA Champions League Final in Lisbon after disposing of title-holders Bayern Munich in the semi-finals.
Saturday's clash in Portugal's capital will be Real's first appearance in a Champions League final since they edged Bayer Leverkusen in 2001.
And Ronaldo, who has already tasted European glory with Manchester United, is upbeat about Real's chances of claiming a 10th-combined European Cup/Champions League trophy, as he returns to his homeland.
"Atletico are doing very important things, they've won La Liga and they are very motivated," said the 29-year-old, who has declared himself fit for the final.
"They've played well in the Champions League and that's why they are in the final but it's a 50/50 final.
"As I said before it's going to be a tough match that will be defined by the little details and I'm sure that Real Madrid will win."
Ronaldo added: "Obviously this is the title that we all want, especially Real Madrid because it will be our 10th Champions League.
"I signed for Real Madrid to win titles, especially this one because it's a great title that I had the opportunity to win with Manchester United and that was one of the most incredible experiences I've had until now.
"So I want to feel that again and I hope that it's a beautiful night and that Real Madrid wins."
Meanwhile, Real goalkeeper Iker Casillas admits going head-to-head with Diego Simeone's men will be difficult but believes his team deserve to end their trophy drought in Europe.
"We know that it won't be easy. We're going up against a fantastic opponent," Casillas said.
"They aren't just a city rival, but rather an opponent in all of our national competitions.
"We'll see how it goes. I truly hope that we win this European Cup, above all for the Madridismo (Madrid fans), since they have suffered for the last few years.
"I believe that Real Madrid deserves to finally win this trophy."
