Providing additional tactile sensory input, such as light finger touch, improves postural control while standing. This phenomenon is called light touch (LT) effect. The present study investigated influences of tactile sensitivity in a finger on the magnitude of improvement in postural sway owing to LT. The participants were 16 healthy men (20-33 years). They performed two upright postures with their eyes closed; their feet 1) comfortably apart (normal stance) and 2) together in a side-by-side stance (Romberg stance). These tasks were performed both with and without LT. The participants let their right index finger lightly touch a fixed surface. The tactile sensitivity in the finger was evaluated using a two-point discrimination test. Although postural sway decreased owing to the LT, the association between tactile sensitivity in the finger and the percentage change in postural sway was not statistically significant, regardless of the difficulty of the upright tasks. These results suggested that the person might not be able to perceive a change in direction in their posture through LT; however, the LT might be recognized as a reference point to detect relative changes in the alignment of the body. Therefore, tactile sensitivity in the finger might not be necessary to achieve the LT effect.