Objective: To examine the occurrence of oppositional defiant disorder (ODD) symptoms in a general population of boys and girls, as reported by parents and teachers, and to investigate differences in prevalence estimates, depending on how parents' and teachers' ratings were combined. Method: Data were collected from 7007 children (aged 7-9) who participated in The Bergen Child Study (BCS), an ongoing population-based study of children's development and mental health. ODD symptoms were measured by the SNAP-IV (Swanson, Nolan, & Pelham-IV) Oppositional Defiant Disorder sub-scale (SNAP-IV ODD) that was distributed to parents and teachers. Co-occurring symptoms of mental health problems were measured by the Strengths and Difficulties Questionnaire (SDQ). Results and Conclusion: Prevalence-estimates of ODD varied considerably depending on how ratings from parents and teachers were combined. Specific ODD symptoms occurred at very different rates depending on the rater and on the gender of the child being rated. Parents and teachers co-identified very few children with ODD. ODD identified by only one informant was associated with high levels of comorbid mental health problems and impairment according to both informants. The results support an informant-specific conceptualization of childhood ODD.