Findings from a large number of studies indicate that language plays a significant role in controlling our behavior. Inner speech has been shown to be an important factor in the control of executive functions through different variations of executive control tasks (Miyake et al., 2004; Kray et al., 2009; Tullet and Inzlicht, 2009). In order to investigate the role of inner speech in the inhibition of impulsive response, a Go/No-Go task was used. Participants took part in regular or switching version of the Go/No-Go task while completing verbal and spatial secondary task. We expected that participants in the verbal condition would have a more impulsive response compared to the spatial condition, and the differences would be more pronounced in the switching version. The results of the research did not entirely confirm these expectations. It was found that participants in the regular version were more impulsive in the verbal condition, while in the switching version they were more impulsive in the spatial condition. Although the findings suggest an important role of inner speech in self-control behavior, further studies are needed.