This dataset is taken from the study "Handedness Does Not Impact Inhibitory Control, but Movement Execution and Reactive Inhibition Are More under a Left-Hemisphere Control" by Mancini et al. (Symmetry 2021, 13(9), 1602; https://doi.org/10.3390/sym13091602). The paper assesses reactive and proactive inhibitory control in a large sample of left- and right-handers (n = 52). Each participant completed two reaching versions of the stop-signal task, one using the right arm and one using the left arm. The main dependent variables were the stop-signal reaction time (SSRT), movement times (MT), reaction times, frequency of the 'context effect' (Mirabella et al. Cogn Neuropsychol. 2008 Oct-Dec;25(7-8):996-1010). Data shows that reactive and proactive inhibition do not differ according to handedness. However, while proactive inhibition is similar for the two hands, the SSRT of the right arm is shorter than that of the left arm. In addition, participants showed faster MTs with the right than with the left arm. We interpret our results in light of the dominant role of the left hemisphere in some aspects of motor control.