Touted freshman center Adam Woodbury scored 10 points in his college debut for the Hawkeyes, who opened the game with a 17-2 lead.
The Broncs cut Iowa's early lead to 33-22 with 2:52 left in the first half, but the Hawkeyes ended the half on a 12-2 run. Iowa cruised in the second half.
Devyn Marble, Iowa's leading returning scorer, had 10 points.
Friday's attendance of 14,859 fans was Iowa's largest for a season opener since 2001.