Event-related potentials were recorded while five-year-old children completed a Go/No-Go task that distinguished between partial inhibition (i.e., response is initiated but cancelled before completion) and successful inhibition (i.e., response is inhibited before it is initiated). Partial inhibition trials were characterized by faster response initiation and later latency of the lateral frontal negativity than successful Go and successful inhibition trials. The speed of response initiation was influenced by the response speed on previous trials and influenced the response speed on subsequent trials. Response initiation and action decision dynamically influenced each other, and their temporal interplay determined response inhibition success.