Previous studies have reported that rearing cats with monocular deprivation produces a reduction in lateral geniculate Y-cells that can be driven by the deprived eye. We investigated whether the loss of responsive Y-cells is due to a cortico-fugal suppression from areas 17 and 18. Monocularly deprived cats had visual cortex removed when they were adults, and single cell recordings were made in the lateral geniculate nucleus immediately afterward. These animals showed the same loss of Y-cells as monocularly deprived control animals with intact visual cortex. Therefore, in contrast to other visual system structures (superior colliculus and lateral suprasylvian visual cortex), cortico-fugal suppression does not appear to underly the inability of the deprived eye to drive cells in the lateral geniculate nucleus.