Objective: To address the issue of response time (RT) profiles in hyperactive-impulsive (ADHD-HI), inattentive (ADHD-IA), and combined (ADHD-C) subtypes of ADHD. We hypothesized that children with ADHD-HI should respond more rapidly than children without ADHD and children with ADHD-IA and ADHD-C should respond more slowly than children without ADHD. Method: Four groups (3 ADHD groups and 1 non-ADHD group) each composed of 16 children (7-13 years old) performed a visuospatial choice task. Results: ANOVA indicated very variable RTs for each ADHD subtype when controlling for individual RT. ANOVA performed on RT distribution showed significant differences between the ADHD and non-ADHD groups: biased to fast responses in ADHD-HI and biased to slow responses in ADHD-IA and ADHD-C. Conclusion: The results suggest that response time profiles were abnormal in all ADHD subtypes and were markedly different between children meeting criteria for ADHD-HI and those meeting criteria for ADHD-IA or ADHD-C. (Contains 2 tables and 2 figures.)