Variety liked it:

Finally, someone’s found a sure-fire way to make money with a modern Middle East war movie: Just send a Marvel superhero into the fray to kick some insurgent butt. The powerhouse comicbook-inspired actioner “Iron Man” isn’t principally about this fantasy, but it won’t hurt at least American audiences’ enjoyment of this expansively entertaining special effects extravaganza. Having an actor as supercharged as Robert Downey Jr. at the center of such a tech-oriented enterprise reps a huge plus, and Paramount should reap big B.O. rewards by getting out ahead of the summer tentpole pack with such a classy refitting of an overworked format.

It’s refreshing, for a start, that the character suddenly endowed with superpowers isn’t a dweeby teen, but rather a pushing-middle-age genius who is himself entirely responsible for the advanced means he acquires to combat his adversaries; even more than the latest incarnation of Batman, he’s a self-made superman. And while we’ve seen plenty of masks and gravity-resistant heroes before, the outfit sported by the main man here, which looks as though it was made by a top ski boot manufacturer, is striking and capable of great things.