In the modern world, writing by hand is increasingly being replaced by typing on a keyboard. However, the available evidence on the neural mechanisms underlying these writing modalities comes primarily from international studies. This comparative study aimed to test the hypothesis that writing by hand elicits a greater increase in oxygenated hemoglobin concentration in the motor cortex and in regions overlying the angular and supramarginal gyri than keyboard typing. We used a within-subject repeated-measures design with two levels of each independent variable: stimuli reproduction modality (writing vs. typing) and stimuli presentation modality (visual vs. auditory). Brain oxygenation was recorded using functional near-infrared spectroscopy (fNIRS). The sample consisted of 62 individuals aged 18–35 years; data from 38 participants were included in the analysis: 8 men (21.1%) and 30 women (78.9%), with a mean age of 21.2 years. Group comparisons were performed using the Wilcoxon signed-rank test with Holm–Bonferroni correction. In the initial analysis, differences in oxyhemoglobin concentration in the motor region were close to statistical significance: handwriting vs. keyboard typing, p = 0.034; handwriting vs. keyboard typing under visual stimulation, p = 0.010; and visual vs. auditory stimulation during handwriting, p = 0.015. However, after correction for multiple comparisons, these differences no longer reached statistical significance (p = 0.068, 0.080, and 0.105, respectively). No significant differences were observed in the region of the angular and supramarginal gyri. Thus, the hypothesis was not supported. Nevertheless, the observed near-significant effects and the sensitivity of fNIRS to differences between writing modalities may be regarded as preliminary findings and a promising direction for future research.