1990 Leaf Baseball card fronts have a simple but distinct design. A bright player photo is surrounded by a thick white border. The bottom border has the player's name and position in a somewhat generic font. The most catching design element is the grey stripe effect in the bottom left of the photo, next to the team logo. Card backs are in full color, offering career stats, a small photo of the player's face and the main biographical details. For younger players, written biographies are used to filled up the space.

Rookies of Frank Thomas and Sammy Sosa have long been the key cards in 1990 Leaf Baseball, but there are a handful of other strong options as well. These include Larry Walker, Dave Justice, John Olerud, Marquis Grissom and Carlos Baerga. The set is also popular enough that key veterans like Cal Ripken Jr, Barry Bonds, Ken Griffey Jr and Nolan Ryan are still in demand.