Aggravated crime against nature is a legal term used in Louisiana to describe certain circumstances under which a crime against nature is committed. A crime against nature is defined as unnatural carnal copulation by a human being with another of the same sex or opposite sex, except for the purposes of procreation. The term "aggravated" is used when the crime is committed under certain circumstances, such as when the victim resists the act to the utmost but such resistance is overcome by force, or when the victim is prevented from resisting the act by threats.

The penalties for committing an aggravated crime against nature in Louisiana are severe. The offender can face imprisonment at hard labor for not less than three nor more than fifteen years, without benefit of suspension of sentence, probation or parole. If the victim is under the age of thirteen years and the offender is seventeen years or older, the offender can be punished by imprisonment at hard labor for not less than twenty-five years nor more than ninety-nine years, with at least twenty-five years of the sentence imposed to be served without benefit of parole, probation, or suspension of sentence.

It is important to note that the definition of "crime against nature" and the penalties for committing such a crime can vary by state or jurisdiction. While Louisiana and a few other states such as Kansas and North Carolina still maintain the title of the law including the aggravated crime against nature, other states may have different laws or terminology for similar offenses.