Disparity in diagnosis and treatment of attention deficit hyperactivity disorder (ADHD) among children has been studied; however, no known studies examining disparities based on severity of symptoms have been investigated. The purpose of this study was to assess the racial disparities in diagnosis and treatment that exist among children based on severity of symptoms. This cross-sectional quantitative analysis used data from the 2016 National Survey of Children’s Health and the theoretical foundation was guided by the behavioral model of healthcare utilization and help-seeking behavior for ADHD. Binomial logistic regression analysis showed an overall association between race and the diagnosis and treatment of ADHD. The greatest disparities were observed among Hispanic children who were less likely to be diagnosed with ADHD (OR = 0.718 [0.616, 0.838], p < .001) and less likely to receive medication (OR = 0.638 [0.520, 0.784], p < .001) compared to non-Hispanic White children. While non-Hispanic Black children were also less likely to be diagnosed with ADHD (OR = 0.932 [0.770, 1.130], p = .474) and less likely to receive medication (OR = 0.899 [0.698, 1.158], p = .409) compared to non-Hispanic White children, these results were not statistically significant. When severity of symptoms was considered, non-Hispanic Black children with mild or moderate symptoms were less likely to receive medication compared to non-Hispanic Whites. However, the association was only statistically significant among Hispanic children. No difference was observed when symptoms were severe. Implications for positive social change include implementing targeted public health policies and effective programs to improve ADHD management among Hispanic and non-Hispanic Black children.