Sex-selective abortion is the practice of aborting an otherwise-desired fetus after a determination (usually by ultrasound but also rarely by amniocentesis or another procedure) that the fetus is of undesirable sex. The aborted fetus is usually female.

Sex-selective abortion was rare before the late 20th century because of the difficulty of determining the sex of the fetus before birth. It is believed to be responsible for at least part of the skewed birth statistics in favor of males in Mainland China, India, Taiwan, and South Korea. Although the practice is often illegal, laws against it are extremely difficult to enforce because there is no practical way to determine the parents' true motivation for seeking an abortion.

Parents may wish for a male child because in many cultures only a male will carry on the family name, because they believe that a male is needed for work, or because they wish a male to earn an income needed to support the parents in their old age.

In response to sex-selective abortions, Mainland China has made it illegal for a physician to reveal the sex of a fetus.

See also Sex-selective infanticide