The Stroop Interference Test is widely used to assess the inhibition function; however, divergent results have emerged from meta-analyses in children with ADHD. This has led to conflicting results as to whether the Stroop test detects the level of inhibition in these children. We hypothesized that the general approach to include interference scores depending on response time causes conflicting results, whereas recordings of errors may prove a superior measure of the inhibition function in children with ADHD. In the present study, 39 children with an ADHD diagnosis, two subgroups with and without another comorbid mental health disorder, were compared with respect to their interference scores of response time and errors with two subgroups of children with no ADHD. The two subgroups comprised 33 children with another mental health disorder other than ADHD and 56 children with no psychiatric disorder. The between-group analyses detected a multivariate, marginal main effect of an ADHD diagnosis on the Stroop interference scores, and a univariate main effect of an ADHD diagnosis on the interference score of errors. Further, only the interference score of errors predicted significantly the parent reported scores on the Inhibit scale from the Behavior Rating Inventory of Executive Function. These findings support that a Stroop interference score of errors is sensitive for inhibition problems in children with ADHD and encourages the use of Stroop versions including error recordings independent of response time.