Aims: To compare the usefulness of DSM IV and ICD-10 DCR criteria in clinic children presenting with the symptoms of inattention and hyperactivity-impulsivity. Methods: 62 children (54 boys and 8 girls) participated in the study. Children were assessed on Kiddie schedule for affective disorders and schizophrenia--present and lifetime version and then diagnosed as attention deficit/hyperactivity disorder (ADHD) or hyperkinetic disorder (HKD) as per DSM IV or ICD-10 DCR criteria. Comorbidities were diagnosed as per DSM IV criteria. Severity of symptoms was rated using Hillside Behavior Rating Scale (HBRS) while global assessment of functioning was assessed on Children's Global assessment Scale (CGAS). Results: All could be diagnosed with ADHD however, only 44 (71%) could be diagnosed as HKD. There was no statistically significant difference in most sociodemographic variables, severity of illness on HBRS and impairment on CGAS of the subjects diagnosed with ADHD and HKD and subjects with ADHD but not HKD (non-HKD-ADHD). Conclusions: DSM IV should be used because it diagnoses more children with impairing symptoms of inattention and hyperactivity-impulsivity as compared to ICD-10 DCR. Also, there is a significant overlap in between ADHD and HKD. (Contains 2 tables.)