The presence of inattention and hyperactivity-impulsivity symptoms, as defined by the DSM-IV, is analysed in a group of children aged 4-12 from Barcelona, using information provided by parents and teachers. Two rating criteria were defined: broad and narrow. The frequency of symptoms depends on the type of behaviours evaluated - inattention or hyperactivity-impulsivity - and on the sex and age of the subjects assessed and of the informants. The agreement between informants is analysed and the suitability of using a single cut-off point, regardless of age and sex, is discussed.