Transcranial direct current stimulation is a non-invasive neuromodulation method aiming to improve a range of motor and cognitive functions. This study aimed to determine whether one session of anodal transcranial stimulation applied to the left dorsolateral prefrontal cortex with a direct current of 1.5 mA can improve executive functions, specifically working memory and inhibition. This was achieved by dependently measuring the effect of anodal and sham stimulation on performance improvement in the backward digit span, n-back and Stroop tasks on a sample of 21 young adult subjects. A control measure of perceptual speed was also applied to determine the specificity of neuromodulation effects. A significant interaction of the stimulation condition and the measurement point on the performance of the backward digit span task was obtained, whereby subjects demonstrated an increase in the extent of the maximum sequence reproduced backwards after anodal stimulation compared to the measurement before stimulation, while the same was not shown in the sham condition. There was no significant difference in the performance of the n-back task between the anodal and sham sessions, but the interaction of the stimulation condition and their assigned schedule was obtained - it was shown that when the anodal stimulation was applied in the second session, a significantly higher proportion of accuracy occurred on the n-back task due to anodal compared to sham stimulation. Anodal stimulation did not produce a significant difference between pre- and post-measures of inhibition on incongruent stimuli in the Stroop task compared to the sham session. Finally, there was a significant interaction of stimulation condition and measurement point on the adjusted measure of perceptual speed, indicating that there was a greater pre-post acceleration when anodal stimulation was applied, compared to the sham condition. The findings point to the active role of the DLPFC in the processes of working memory and perceptual speed, and to the potential of atDCS in improving these functions.