The ADHD Rating Scale-IV is a norm-referenced checklist designed to assess symptoms of attention deficit/hyperactivity disorder (ADHD) according to DSM-IV criteria. It includes two subscales: Inattention and Hyperactivity-Impulsivity, with 9 items each. The scale is completed by parents or teachers on a 4-point Likert scale, measuring symptom frequency over the past 6 months. It is available in home and school versions, with the home version also in Spanish. The scale takes about 5 minutes to complete and provides normative data for ages 5 to 18. The scale has adequate reliability and validity, with high internal consistency and test-retest reliability. However, some technical aspects suggest caution, particularly with minority populations. The standardization sample closely matches 1990 census data on ethnicity and region, but limited information is provided on socioeconomic status, urban/rural residence, and parent education levels. The scale may overidentify African American children, and data for the ADHD primarily hyperactive-impulsive subtype are limited. The ADHD Rating Scale-IV is useful as a screening tool and can be used to evaluate treatment outcomes using the Reliable Change Index (RCI). It is user-friendly and time-efficient for parents, teachers, and clinicians. However, it should be used in conjunction with other measures for accurate diagnosis, especially for subtype-specific assessments. Despite its limitations, the scale is a valuable tool for initial ADHD referrals and treatment monitoring.The ADHD Rating Scale-IV is a norm-referenced checklist designed to assess symptoms of attention deficit/hyperactivity disorder (ADHD) according to DSM-IV criteria. It includes two subscales: Inattention and Hyperactivity-Impulsivity, with 9 items each. The scale is completed by parents or teachers on a 4-point Likert scale, measuring symptom frequency over the past 6 months. It is available in home and school versions, with the home version also in Spanish. The scale takes about 5 minutes to complete and provides normative data for ages 5 to 18. The scale has adequate reliability and validity, with high internal consistency and test-retest reliability. However, some technical aspects suggest caution, particularly with minority populations. The standardization sample closely matches 1990 census data on ethnicity and region, but limited information is provided on socioeconomic status, urban/rural residence, and parent education levels. The scale may overidentify African American children, and data for the ADHD primarily hyperactive-impulsive subtype are limited. The ADHD Rating Scale-IV is useful as a screening tool and can be used to evaluate treatment outcomes using the Reliable Change Index (RCI). It is user-friendly and time-efficient for parents, teachers, and clinicians. However, it should be used in conjunction with other measures for accurate diagnosis, especially for subtype-specific assessments. Despite its limitations, the scale is a valuable tool for initial ADHD referrals and treatment monitoring.