Dentists and denture wearers have reported that the regular use of a denture cleanser causes whitening of dentures. The whitening effect of denture cleansers on acrylic resin dentures was investigated using four different types of agents on six different types of acrylic resin discs. The color values of the samples were measured using a reflectometer. The greatest whitening effect was seen on autopolymerizing acrylic resins for one of the denture cleansers with all the resins tested.