This article two studies that examined the effect of similarity of location and temporal intensity patterns of the conditioned stimulus (CS) and the unconditioned stimulus (UCS) on the acquision of conditioned suppression. Experiment 1 showed that greater suppression occurs during a stimulus generalization test when the tested stimulus has a location and temporal intensity pattern that is similar to the previously presented UCS. Experiment 2 showed that conditioned suppression is acquired more rapidly if the CS and UCS have similar locations and temporal intensity patterns. These similarity factors were interpreted as forms of event covariation, which aided in associative formation. Several applications of these data are discussed.