Last year, Ronaldo scored a second-leg hat-trick as Real edged out Bayern in a thrilling quarter-final after extra time.
"I hope Ronaldo does not have a good day," said the 72-year-old Heynckes, who coached Madrid to Champions League glory in 1998.
Real are bidding for a record-extending 13th European Cup and third in a row, while five-time champions Bayern were the last side to lift the trophy three years on the spin 42 years ago.
Heynckes said that tradition is more important than spending power, pointing to the exits of Paris Saint-Germain and Manchester City.
"Look at Paris or Manchester City," he said. "You can't buy the Champions League these days. You need time and patience to grow. The players must know each other and respect each other."
The two teams have never gone head-to-head in a final, but this will be their 12th meeting in the knockout stage of the competition and their seventh semi-final clash.
"Real again? Incredible!" midfielder Thiago Alcantara told the Bayern website.
Bayern have won four of the six previous last-four ties between the two clubs, starting with a 3-1 aggregate victory when the clubs first met in 1976.
Forward Thomas Mueller looked back to Bayern's last victory over Real, saying: "I recall the last time we met Real in the semi-finals under Jupp Heynckes in 2012. We won. For me, that's an omen."
Sergio Ramos, Kaka and Ronaldo all missed as Bayern won a penalty shoot-out six years ago, only to lose the final on home soil to Chelsea.
Just before the draw, Bayern announced that Niko Kovac will take over from the outgoing Heynckes as coach at the end of the season.
Heynckes, who led Bayern to the 2013 title with a 2-1 final victory over Borussia Dortmund, knows that the final in Kiev on May 26 would be the last match of his fourth stint in charge.
Club chief executive Karl-Heinz Rummenigge insisted Bayern, who have already clinched the Bundesliga title, are underdogs against a Real side lying fourth in La Liga.
"We are meeting the winner of the last two years," Rummenigge said. "We already know who are the favourites."
Club president Uli Hoeness, who played alongside Rummenigge in the Bayern outfit that won the 1976 title, added: "If you want to win the Champions League, you have to beat the best."
Veteran Dutch winger Arjen Robben, a former Real player, called the clash "a delicacy for all football lovers".