The Colavita visual dominance effect refers to the phenomenon whereby participants presented with unimodal auditory, unimodal visual, or bimodal audiovisual stimuli in a speeded discrimination task, fail to respond to the auditory component of bimodal targets significantly more often than they fail to respond to the visual component. The Colavita effect was demonstrated in this study when participants were presented with unimodal auditory, unimodal visual, or bimodal stimuli (in the ratios 40:40:20, Experiment 1; or 33:33:33, Experiment 2), to which they had to respond by pressing an auditory response key, a visual response key, or both response keys. The Colavita effect was also demonstrated when participants had to respond to the bimodal targets using a dedicated third (bimodal) response key (Experiment 3). These results therefore suggest that stimulus probability and the response demands of the task do not contribute significantly to the Colavita effect. In Experiment 4, we investigated what role exogenous attention toward a sensory modality plays in the Colavita effect. A significantly larger Colavita effect was observed when a visual cue preceded the bimodal target than when an auditory cue preceded it. This result suggests that the Colavita visual dominance effect can be partially explained in terms of the greater exogenous attention-capturing qualities of visual versus auditory stimuli.