The ADHD Rating Scale-IV attempts to measure behaviors associated with ADHD and its DSM-IV subtypes. The scale was developed to closely approximate the DSM-IV diagnostic criteria for ADHD primarily inattentive subtype, ADHD primarily hyperactive-impulsivity subtype, and ADHD combined subtype. This is an 18-item scale to be completed by the parent and/or guardian or teacher of a 4- to 20-year-old student. There are two separate versions of this scale: the home (also available in Spanish) and the school version. The administration of both versions is preferable, particularly for subtype specification. The ADHD Rating Scale-IV has adequate reliability and validity, although some of the technical aspects suggest caution when using this scale. The standardization sample closely matches the 1990 census data on ethnic group and region. However, limited and generalized information is provided on the socioeconomic status of the participants. No information is provided on the urban/rural residence status and the parent education levels of the norm population. Limited information is provided on the education classroom for the normative participants (i.e., special education vs. general education). The only information provided is for the school version normative group (91% general education and 8% special education), and then there is no discussion of how this breakdown compares to the school district or the population in general. The limited cell size for ethnic groups restricts interpretation of the ADHD Rating Scale-IV with minority populations. Data were not provided separately for different ethnic groups. The authors caution a possible overidentification of African Americans. When sample participants were grouped by ADHD subtype, no individuals qualified for the ADHD primarily hyperactive-impulsive subtype. This limits the use of the ADHD Rating Scale-IV as a measure of this subtype. Considering the low specificity ratings for the ADHD primarily inattentive and ADHD combined subtypes, this scale should be used with caution and in conjunction with other measures for subtype specific diagnoses. The ADHD Rating Scale-IV has other limitations as well. As mentioned, the ADHD Rating Scale-IV results are limited for use with ethnic minority groups, particularly African Americans. In general, more research is needed to determine the best use of the ADHD Rating Scale-IV as it differs by setting, version (home or school), referral source, and subtype functioning. Nonetheless, many clinicians will find the ADHD Rating Scale-IV a useful screening tool. It is user friendly and time efficient for the parent, teacher, and clinician. It can also be a valuable tool as a treatment outcome measure when employing the RCI formula, assuming a pretreatment rating is obtained. The ADHD Rating Scale-IV is a good tool for gathering essential information in an initial ADHD referral despite its limitations