Match a tube of finishing putty, designed specifically for Pergo flooring, with the color of your floor. If you do not have a Pergo retailer in your area, you can substitute the finishing putty for a similar colored wood putty, which is available at any home improvement store.
Slide a pair of rubber gloves on your hands. Squeeze enough finishing putty on your finger to cover your fingertip.
Press the finishing putty down into the crack in your Pergo floor. Pressure is key so that you fill the entire crack.
Wipe away any putty that rises up out of the crack onto the rest of the floor with a paper towel.
Wait for the finishing putty to dry naturally. Inspect the area. Apply a second layer of finishing putty if the first layer didn't repair the crack so that it is now level with the floor.