Objective: The aim of this study was to examine occurrence of emotional lability (EL) in preschoolers with ADHD symptoms versus controls. Method: The study was part of the Norwegian Mother and Child Cohort Study (MoBa) at the Norwegian Institute of Public Health. In the present study, 495 preschoolers were clinically examined. Symptoms of ADHD, anxiety, and oppositional defiant disorder (ODD) were measured with the Preschool Age Psychiatric Assessment Interview. An EL measure was obtained from the Emotional Control subscale of the Behavior Rating Inventory of Executive Function–Preschool Version (BRIEF-P), which parents and teachers completed. Results: EL was significantly more frequent in the ADHD group compared with controls (25% vs. 7%, p < .001). By parent report, EL correlated significantly with ADHD-, anxiety-, and ODD symptoms. By teacher report, EL was significantly correlated only with hyperactivity-impulsivity. Conclusion: EL appears identifiable in young preschoolers and was particularly associated with ODD in children with ADHD symptoms.