Aims and method To measure compliance with National Institute for Health and Care Excellence (NICE) recommendations in two adult attention-deficit hyperactivity disorder (ADHD) clinics and to guide further service development. We audited the case notes of 150 patients referred to adult ADHD clinics in East Anglia in 2010-2011 against NICE standards using an adapted version of the ADHD audit support tool.Results We found good compliance with NICE standards for diagnosis, assessment and pharmacological treatment of adult ADHD. There was a failure in smooth transitional arrangements from child and adolescent mental health to adult ADHD services. Comprehensive treatment programmes addressing psychological, behavioural, educational and occupational needs were not well developed. Deficiencies were observed in conducting recommended physical examinations. Substance use was prevalent in almost half of ADHD patients.Clinical implications Greater attention is needed in delivering better transitional arrangements and comprehensive treatment programmes for adult ADHD. More structured training with emphasis on ADHD-specific psychological interventions, physical examination and treatment of complex cases, especially with comorbid substance misuse, should be offered to clinicians.