A tubal ligation ("having your tubes tied") is a type of surgery for women that permanently prevents pregnancy (sterilization). During a tubal ligation, the fallopian tubes are closed or removed to prevent fertilization; this blocks the sperms' path to the egg.
The fallopian tubes can be cut, clamped closed, or tied off, or the ends may be sealed by applying heat (cautery). Removing the fallopian tubes is another option.