"If it is the heart speaking, it is France, and I'd also like to say that Algeria can do well at this World Cup," the former French captain and son of Algerian immigrants told media at a promotional event in Geneva.
"But to be logical, I would point to Spain as the favourites for this competition. I would say Spain without hesitation because they have demonstrated over the last few years that they have a great team and one that can do something big at this World Cup."
Zidane played a decisive role in France's World Cup win on home soil in 1998 and their European Championship success two years later.
The former midfielder now expects Spain to complete the same major tournament double in South Africa from June 11 to July 11, following their victory at Euro 2008.
"It reminds me of what we did in 1998 and 2000, in reverse order," he said. "They won the European Championship in 2008 and why not the World Cup? From the French point of view, I hope not, but I can see it happening."
Zidane was part of the France team that knocked Spain out of the last World Cup before going on to reach the final.
His playing career came to an abrupt and inglorious end when he was sent off in the final against Italy for headbutting Marco Materazzi. Italy won the final on penalties.
