This study explored whether reduction of the maximal voluntary force of finger flexor muscles affects response inhibition processing while performing the flanker "inhibitory reaction time" task. Sixteen participants completed two experimental sessions: each consisted of either a fatiguing exercise (fatigue session) or a control task (control session) followed by a flanker task. When responding to 32 compatible and 32 incompatible trials, the participants were asked to respond to a right-facing arrow by pressing a button beneath their middle finger, and to a left-facing arrow by pressing a button beneath their index finger. During the fatigue session, the participants were instructed to sustain 50% of their maximal voluntary isometric force during a handgrip force task with their wrist in a neutral position. In the control session, this exercise was replaced by a 7-min period of rest. The results showed that the handgrip task was effective at inducing a significant decrease in maximal force (-25.2 ± 9.1%, p < 0.001). However, this performance fatigability did not affect either the reaction time or the error rate. Similarly, it did not alter the conflict-monitoring function involved in the settings of response override. A functional robustness of the inhibition function under fatigue effect is assumed, at least in young healthy adults.