A study of the local and migratory effects of free silicone gel taken from a mammary prosthesis is reported. Thirty eight Wistar rats were injected in their subcutaneous space with 1 cm3 of silicone gel. The animals were sacrificed on day: 3, 7, 15, 30, 60, 180, 240, 360, 420, 450. The visceral organs (heart, kidneys, lungs, stomach, gonads, liver, pancreas, spleen, intestine), as well as the tissue adjacent to the region of injection, were histologically analyzed. There was no detectable silicone and no damage to the visceral organs based on routine histopathological analysis. The greatest fibrosis was observed at the extremities of the disk formed by the silicone in the subcutaneous space.