About two days. There’s a lot to see in the park – maybe add an extra day if you plan to go to to the Brazilian side as well.

A three days’ stay is about fine, I agree. But I’d also vouch for expanding a visit to include other great places on the same argentinean province of Misiones. The Jesuit missions, Wanda and some beautiful estancias by the side of the river would make for a unique, out of this world experience (the red-colored soil makes it all look like a dream).

I agree with the others. I spent 3 days there to see the falls from both the Brazilian and Argentinean sides. The Argentinean side has more to see because it’s on the outside of the river bend. On the other hand, the Brazilian side has a great bird park as well as helicopter tours, which is the best way to see the full extent of the falls.

I’d say you can do it in 2 days, but I agree, if you can spend an extra day, you’ll have time to do a few extra things. I went on a boat ride above and below the falls. Loads of interesting flora and fauna to look at.