Research has shown discrepancies between the rates of Attention Deficit Hyperactivity Disorder (ADHD) diagnosis and diverse racial/cultural groups. Whereas ADHD is believed to occur in equal proportions in the Caucasian and African-American communities, African-Americans are far less likely to be diagnosed and treated for ADHD (Hervey-Jumper, Douyon, & Franc, 2006). Research on the systemic problems affecting ADHD treatment has exhibited multiple variables that may affect the rate of diagnosis and access to mental health treatment. While numerous systemic issues may contribute to the lower rates of ADHD treatment in the African-American population, the extent to which clinicians' perceptions as well as their methods of clinical assessment, contribute to the diagnostic discrepancies is unclear. How a clinician navigates systemic issues could impact diagnosis, recommendations, and level of treatment involvement. The clinician's approach to the diagnosis may impact the disproportionate levels of ADHD diagnosis across cultures as well as the type of treatment a child receives. The purpose of this study is to investigate the diagnostic and assessment practices of clinicians for culturally specific themes and how they navigate the systemic issues associated with culturally informed ADHD diagnosis. Participants of the study were psychologists and certified school psychologists who perform ADHD diagnostic assessments on children and/or adolescents and identified as African-American or Caucasian. A qualitative research design using a semi-structured interview was utilized. The interview questions were chosen by the researcher to allow the participants to explore their perceptions and reflections regarding ADHD diagnostic and treatment practices. Of the 10 participants of the study, five of the participants held a doctoral degree of psychology (Psy.D.), two of the participants held a doctoral degree of philosophy (Ph.D.), and three of the participants were certified school psychologists. In total, two of the participants self-identified as black or African-American and eight of the participants self-identified as white or Caucasian. Of the 10 participants, one participant identified as male and nine identified as female. The responses of the participants were analyzed and themes that reflected on their professional experiences with the systemic issues involved in diagnosing and treating ADHD emerged. Overall, the results of this study demonstrated the clinical and diversity challenges that arise when assessing clients for ADHD across cultures. The findings illustrate the clinical utility of culturally informed assessment, the systemic impacts on testing, and the strategies assessment clinicians can use to aid them in their diversity considerations. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]