Young children with disruptive behavior patterns often continue to have significant behavioral and psychological difficulties throughout childhood, adolescence, and even into adulthood. In order to provide the most appropriate and effective interventions for these children, it is important to understand the nature of early-onset externalizing behaviors, including all possible neurocognitive etiological and/or mediating factors. One such factor that needs to be examined is the set of cognitive processes known as executive function. The current study examined the link between certain aspects of executive function and externalizing or disruptive behaviors in preschoolers. Preschool teachers completed a behavior rating scale on children in their classroom to assess levels of disruptive behavior. Forty-seven preschool students participated by completing a battery of individually-administered executive function tasks, and the parent and teacher of each child completed a rating scale of everyday executive behavior. Data analyses revealed that there is a strong, negative correlation between certain aspects of executive function and disruptive behaviors in preschoolers, specifically inhibitory control on cognitive tasks, and inhibitory and emotional control, working memory, planning and organization, and overall executive behaviors as rated by parents and teachers. In addition, children with elevated levels of disruptive behavior differed significantly from control children in regards to mental flexibility (as measured by a cognitive task) and inhibitory and emotional control, mental flexibility, working memory, planning and organization, and overall executive behaviors (as rated by parents and teachers). Clinical implications, limitations of the study, and directions for future research are discussed.