Functional magnetic resonance imaging has been successfully used to map the activation in the lateral geniculate nucleus (LGN) in both hemispheres as well as the primary visual cortex (V1) during a checkerboard visual stimulation. The average blood oxygenation level dependent (BOLD) change in LGN was less than that in V1. However, the BOLD temporal responses were similar between LGN and V1. The activation in the pulvinar nucleus during visual perception was also detected, and its activated location could be separated from LGN in 3D images. The LGN activation between intersubject and intrasubject multiple trials was compared. The results demonstrate that fMRI can reliably and robustly detect small subcortical nucleus activation in the human brain.