Recent studies have suggested that negation comprehension falls back onto inhibitory brain systems that are also crucial for impulse control and other non-linguistic control domains (Beltran et al., 2018, 2019; de Vega et al., 2016; Liu et al., 2020). Against this backdrop, the present pilot study investigated the use of negation within directional instructions (i.e., "not left", "now left", "not right", "now right") in children with ADHD and a control group. The results indicate that children in general have a long response delay following negative compared to affirmative instructions. Additionally, there was a tendency for this effect to be more pronounced in the ADHD group. Together, these results suggest that negation processing might indeed demand inhibitory control processes, which are differently available across different subgroups. Thus, the current study provides evidence that using negation in imperatives or instructions is generally rather critical and should be avoided if possible, but that negation use is probably even more problematic in specific clinical populations. Potential implications of these results will be discussed.