A method to measure gel bleed from intact silicone gel-filled breast implants was developed. This nondestructive technique permits accurate and reproducible serial measurements of silicone bleed from smooth wall breast implants (n=10) under simulated physiologic conditions in vitro. Gel bleed rates from new low bleed gel-filled implants and intact explants (unbarriered, low bleed, double lumen) were determined. These results demonstrate the reliability of this method to quantify silicone gel bleed and may permit a meaningful comparison of bleed rates from implants in the future.