AIMS: In a sample of newly diagnosed children with attention-deficit/hyperactivity disorder (ADHD), the aims were to examine (1) paediatrician assessment and management practices; (2) previous assessments and interventions; (3) correspondence between parent-report and paediatrician identification of comorbidities; and (4) parent agreement with diagnosis of ADHD. METHODS: DESIGN: cross-sectional, multi-site practice audit with questionnaires completed by paediatricians and parents at the point of ADHD diagnosis. SETTING: private/public paediatric practices in Western Australia and Victoria, Australia. MAIN OUTCOME MEASURES: paediatricians: elements of assessment and management were indicated on a study-designed data form. Parents: ADHD symptoms and comorbidities were measured using the Conners 3 ADHD Index and Strengths and Difficulties Questionnaire, respectively. Sleep problems, previous assessments and interventions, and agreement with ADHD diagnosis were measured by questionnaire. RESULTS: Twenty-four paediatricians participated, providing data on 137 patients (77% men, mean age 8.1 years). Parent and teacher questionnaires were used in 88% and 85% of assessments, respectively. Medication was prescribed in 75% of cases. Comorbidities were commonly diagnosed (70%); however, the proportion of patients identified by paediatricians with internalising problems (18%), externalising problems (15%) and sleep problems (4%) was less than by parent report (51%, 66% and 39%). One in seven parents did not agree with the diagnosis of ADHD. CONCLUSIONS: Australian paediatric practice in relation to ADHD assessment is generally consistent with best practice guidelines; however, improvements are needed in relation to the routine use of questionnaires and the identification of comorbidities. A proportion of parents do not agree with the diagnosis of ADHD made by their paediatrician.