Anodal transcranial direct current stimulation (tDCS) over the leg area of the contralateral primary motor cortex (M1) improves fine motor control of the ankle in healthy adults. However, the effect of cathodal tDCS over the leg area of the ipsilateral M1 via disinhibition of inter-hemispheric inhibition from a stimulated M1 remains unknown. The aim of this study was to test a hypothesis that cathodal tDCS over the leg area of the ipsilateral M1 also facilitates fine motor control of the ankle in healthy subjects. Healthy subjects were assigned randomly to three tDCS conditions (anodal, cathodal, or sham) in a single-blind manner. In all conditions, the subjects practiced tracking a sinusoid waveform using dorsiflexion-plantarflexion movements of their ankle. Then, all subjects performed the same task again at 1 and 24 h later. The results indicated that the dorsiflexion-plantarflexion movements during intervention were improved significantly in the anodal group compared with the sham group, whereas there was no difference between the cathodal and sham groups. At 1 and 24 h after tDCS, there was no difference between the three groups. These findings are useful for the development of neuro-rehabilitation.