OBJECTIVES: Attention Deficit/Hyperactivity Disorder (ADHD) is one of the most commonly diagnosed behavioral disorder among children. Main goal of the treatment of ADHD is to reduce the symptoms of ADHD and improve physical and mental functioning. Different factors affect utilization of ambulatory care by ADHD patients. Our knowledge of these factors, however, is limited. This study tries to fill this gap. Results from this study can help in identifying factors that might be helpful in reducing disparity in ambulatory care received by ADHD patients. METHODS: This study used data from 2003-2008 Medical Expenditure Panel Survey (MEPS). Sample consisted of patients with ADHD who were identified using International Classification of Diseases, ninth revision, Clinical Modification (ICD-9-CM) codes. Independent variables were selected based on previous studies in the area of ambulatory visits utilization. Negative binomial regression at a 5% significance level was conducted to estimate the relationship between patient characteristics and number of patient's visit to the office based physicians. RESULTS: Prevalence of ADHD was 1.59% (n=28,355,049). Most of the patients were male (66.57%), less than/equal to17 years old (66.14%), White (84.16%), and had private health insurance (65%). Females had 1.28 times (Incidence Rate Ratio (IRR) - 1.28, 95% CI:1.09 -1.51) higher rate for number of visits to the office based physicians when compared to males. Blacks had 31% (IRR-0.69, 95% CI:0.53-0.89) lower rate of ambulatory care utilization when compared to Whites. Publicly insured individuals had 66% (IRR-1.66, 95% CI:1.26-2.18) higher rate of ambulatory care utilization whereas uninsured individuals have 37% (IRR-0.63, 95% CI:0.40-0.99) lower rate of ambulatory care utilization than the ADHD patients with private health insurance. CONCLUSIONS: Gender, and racial disparities exist in ambulatory care utilization among ADHD patients. Providing some kind of health insurance coverage might help in reducing these disparities and optimizing ambulatory care utilization among ADHD patients.