One type of malocclusion in the primary dentition is posteri crossbite caused by premature deflective occlusal interferences. The primary canines are the teeth that most frequently contribute to a laterally guided centric occlusion that creates a functional malocclusion. Because this is not a self-corrected situation, these types of posterior crossbites should be identified early and evaluated for possible corerction through occlusal equilibration. A case that illustrates early correction of a unilateral functional posterior crossbite by equilibration and the 5-year results are presented.